First off let me state.... I used the search feature on your site to find the answer - no luck. I tried to figure out which catagory it would be in... no luck... forgive me if it exists and I didn't find it... but hey, this is my first post to this forum.

And now for something completely different....

http://www.radekaphotography.com/images/gas%20pump%20large.jpg

I have read a ton of threads about how people are boasting the 0-60, the top speed, the sound, the lighting, etc... nothing about boasting the mpg. Is it a doable mod for a realistic price? What would it take and how much (roughly) would it set you back, and for mow much gain? Is there a series of mods which work best?

Um.

I have gotten 37 mpg on trips. I usually get 29-30 mpg. I am more than happy with that, and I would not want to sacrifice performance or my time or money to bump my mileage. The mileage is a number that you can't show off like a nice paint job or stereo, as such, it's not one which (most) people feel is worth their time to try to boost.

Besides, wouldn't an xA be a more logical starting vehicle... same drivetrain and much more aerodynamic.

With that being said, superlight wheels, CAI, underdrive pulleys, and changing the gearing should all help.

...The mileage is a number that you can't show off like a nice paint job or stereo...If gas prices go up much more, it will be the single best thing about these cars. You will soon be bragging about your gas milage.

...The mileage is a number that you can't show off like a nice paint job or stereo...If gas prices go up much more, it will be the single best thing about these cars. You will soon be bragging about your gas milage.

I know it's a great characteristic, but you don't see people putting vinyls on their cars reading "34mpg Highway" now do you?

Besides, wouldn't an xA be a more logical starting vehicle... same drivetrain and much more aerodynamic.
<cheap shot>

Ya... like that's difficult!

</cheap shot>

:rofl:

...but you don't see people putting vinyls on their cars reading "34mpg Highway" now do you?

Yet!

Just because you can't see the improvement doesn't mean it's not a mod worth doing. There is a thread on this site about a guy who bumped his prius up to 80mpg. I know that isn't going to happen on a scion, but am interested in seeing what it takes to sqeeze out a little more from each gallon.

Do any of the performance accessories, if driven right, will boast the mpg? Maybe a new exhaust or air intake? Better air filter setup? If it allows the engine to run easier - it should also boast mpg or am I way off on this?

Do any of the performance accessories, if driven right, will boast the mpg? Maybe a new exhaust or air intake? Better air filter setup? If it allows the engine to run easier - it should also boast mpg or am I way off on this?

You have the right idea.

I know my CAI helped. I think my exhaust helped. Not sure about my lighter wheels since it got real hot right when I got them and I run the A/C all the time.

NOS will not help.

I hadn't considered the effects of running the a/c....

In my truck with the 5.3 V8, it doesn't even notice whether the a/c is on or not. Tons of power without any noticable dip in mpg... but I didn't get it for the mpg... that's what the XB is for.

Is it like the econo cars from the 70's, where you could feel the power hit when you put on the a/c in the XB?

Let's put it this way....
You know how when you're driving down the road a little faster than you should be and all of a sudden, you see a cop doing radar....and you don't want to hit your brakes because he'll see the brakelights? Well, with the xB, all you have to do is turn on the A/C!!! Instant 5 MPH drop with no brakelights!

:silly: j/k it's not that bad.

I brag about the milage al the time, all my freinds have guzzlers. I just checked it again yesterday and got another 37... not bad for almost all highway driven. My secret... draft the semi's. Less air against the front of the XB the better the car moves down the road. Many times I'm off the gas more than on it. I do wish there was a way to re-gear these things, I would love to get the rpm's down on the highway a little. I see larger diameter tires in my future, it'll help on highway milage for as much as I drive.

I brag about the milage al the time, all my freinds have guzzlers. I just checked it again yesterday and got another 37... not bad for almost all highway driven. My secret... draft the semi's. Less air against the front of the XB the better the car moves down the road.

I love hearing my coworkers complain about gas. They drive big trucks and one guy has a H2. Seriously, they complain every day, I love it.

I keep my distance from whe semis... they kick up too much road debris.

For best mpg, keep it stock and drive it slow.

gas prices= booooooooo

was getting 27 in city, then did mod for Ground Wire kit.
Now getting 30 city on a regular basis.
If I keep it 75 or under on the hwy can get up to 37.
Trying something I read about Acetone. 2 oz per 10 gal. Been using it past 4 weeks and slowly uping now at 3 oz. My city driving is just past 31 mpg now and the bum-meter says its performing better.

...but you don't see people putting vinyls on their cars reading "34mpg Highway" now do you?

Yet!

Wrong! (kinda :))

We have one of these on my wife's Civic

http://www.cafepress.com/mpgstickers

what's funny is the xB's get better gas mileage on the highway with the air conditioner on and the windows up. The air coming in the windows drags the car down. I get 4 mpg better with the a/c on. problem is i like having the windows down. lol

btw.. i get 39 on the highway (I drive normal) and 32 in town.

I would like to mod the engine DOWNward in displacement. JDM bBs have 1.3L standard

Prius is a didferent engine I guess, but it's 1.1L and this greatly aids highway milage

WHY? because an aero car on level road only needs maybe 8 to 10HP to run along at 60MPH.

Now, the greater the excess displacement , the less efficiently the engine runs and so more gasoline is burned without useful work function.

For "ideal" milage from an xB we'd have an impossible hypothetical: To get best milage on, say, a level road at sixty, let us have a 20HP engine operating at its -peak torque- value. And if this were the case, perhaps this engine would be, say, of .5L (just making up a number).

And in this way you might well obtain 50+ mpg from an xB at 60mph.
And get similarly excellent mpg in city driving but you won't be keeping up
but like as if you were in a Model T (can be done, I used to drive a T exclusively in traffic)

You would not be equipped, however, to pass semi or pull fast over mountains.

heheheheh... a .5L xB would even have to struggle to get up my driveway (1/3 mile that's second geer in my automatic xB), SciFly. :)

(And that's why the Prius has big batteries and a gas engine - so they can both pump out power when the going gets tough.)

The hilly country 'round me is why I get less MPG than many others do with THEIR xB's.

Of course in Florida, isn't the tallest mountain Space Mountain at 175 feet, or something like that? :lol:

what's funny is the xB's get better gas mileage on the highway with the air conditioner on and the windows up...

I could see where the windows open could act as a huge parachute - putting a lot of drag on the car.

Would a ram air set up with a throttle body spacer put more air into the mix, boasting the horsepower allowing the engine to maintain the higher speed with less effort?

I get SUPER good gas miliage. all I do is once a week drive around and find another scion and take the gas out from thier tank. See most scion owners dont have locking gas caps, so they are easy targets.


:rofl: LOL! hahhahaha, just jerking ya guys... the scion gets pretty good gas miliage I love it.

The big question is now, I bet all you are going to go get a locking gas cap now. LOL :rofl:

Just find ways to get the car lighter and drive it like you're 65.

Hey "Jerk", Scions do have a locking gas cap if the car is locked. Think about it....

Walt

Im not sure how much more mpg you could get, but you can swap in the echo final drive. This would lower your RPM at any given speed compared to stock. The only down side is your performance would lack some.

For my first 1000 miles I averaged 35.4 mpg combined 60 city/40 highway driving. Going about 360 miles to fill up-and the tank still has some 2 gallons left.
No mods and regular (85 or 87 octane) unleaded gas. Use the A/C whenever I feel the need--I don't notice any difference using it or not.

The cheapest and best gas mileage mod you can do is called "Block O' Wood". Just go to your local lumber yard, Lowe's, or what have you, you may even have "Block O' Wood" already, and have a piece of wood cut that will fit under your gas pedal so you only get about a half and inch of movement. Now when you get the urge to gun it, "Block O' Wood" kicks in and stops that foolhearty gas gussling action.

On a a more serious note I think they could make cars more fuel efficient if they wanted. I had a '91 CRX HF that got 54 on the highway and 46 in town. It had a 1.5 L engine like ours except the HP rating was lower. The weight is actually very close. Aerodynamically it was much better but then you have to compare the XA to XB and the gas mileage difference is only rated at 1MPG so that shouldn't kill it that much. I can say for sure the gearing in CRX was much higher. So we just need someone to regear their XB like that of the CRX and see if the mileage will go up. I don't have that kind of cash but I'd sure love to see if it works.

Hmmmmmm... According to the spec sheets my wife's 1984 Honda CRX HF weighed 1713 pounds and my 2005 Scion xB weighs 2450 pounds, that's, uh, about 730 pounds difference.

The later Honda's did put on a LOT of weight, though...as well as moving from a 1.3L to a 1.5L engine... :)

(I don't think I could make it home with the 'block-o-wood' mod - I need a fair amount of 2nd gear throttle to make it up the drive to the apartment complex. :) )

Yeah, you can "draft behind semi's" but the money you save on gas, youll pay on a new paint job. Or a new windshield for that matter.....

In the year an 3 months that I have been driving my xB, i have yet to figure out the best way to get the best MPG...

One whole tank, I didnt take the RPMS about 3K: That tank yeilded 31 MPG.

A couple tanks later, I drove the same streets, except I drove the ____ out of the engine... i reved it all the way to 6k a few times and shifted abotu 4.5K.

I GOT THE SAME MPG on both tanks.....so, go figure

Ok. According to http://www.crxsi.com/specs.htm the model CRX I had was 1967 lbs. A good bit lighter than I thought. I must have been thinking of the weight of the Si. So roughly a 500 lb. difference. The big question is, how much is the weight effect. If we could take 500 lbs. out of the XB, would it even get close to the CRX gas mileage? I doubt it plus it would be very hard to get that much weight out the car and it still be useful as a daily driver.

Have to change the final gearing on the xB, too, to give it less agressive ratios to match with the lighter weight.

A 'rule of thumb' for the effect of weight ONLY on fuel consumption (from the Bosch Automotive Handbook) with everything else remaining exactly the same is roughly 1/10 MPG per hundred pounds...

(Darn tpyos!)

Wow!!! Is that all???? I thought it would be higher than that.

Here's the way I see it!!!!
I was an automotive tech (mechanic) for many years .........
When an auto mfgr designs and builds a car that is intended to get good mileage the intake and exhaust are dyno tuned for Mileage not performance!!!! Your vehicles emissions and induction system is computer controlled soo... the more air you let in and out the more fuel will be consumed it's the way an internal combustion engine works,it,s pure physics.
When I put a CAI and cat back on my XB my mileage decreased BUT what a difference in performance....................
wingsaseagles

Most performance modifications will help with mileage *if* you drive very carefully. CAI, exhaust, underdrive pulleys, aftermarket ignition all work. Lightweight wheels, rock-hard tires would help too.

I also wonder about making a spoiler for the back that instead of being used for downforce be used to deflect air down behind the back to reduce vacuum.

Also take as much weight out of it as possible - take out the back seat if you're really comitted.

After that there's things like finding a way to smooth the air flow over the windshield wipers (or remove them altogether). Don't use the A/C, don't use the radio, don't use the lights...



All of these are, of course, assuming you're doing the basics like keep the tires properly inflated and drive the speed limits or something close to it.

I agree with mfbenson. My CAI and TRD exhaust got me about 2 to 2.5 more mile per gallon. The exhaust alone got from about 1 to 1.5 mpg. I drive a very tight loop, so my weekly mileage and driving technique doesn't change much. That's how I can keep such a tight watch on it.

BUT, what I don't understand is how the Ground Wire Mod someone spoke about a few posts ago can get you any more mileage. What am I missing here??

:lalala: I too like it when the guys at work come in saying" it took 65 dollars to fill my truck" and stuff like that , I always get 33-35 mpg by just driving civilized , 60/40 city/hiway driving.stock 5 spd.

Besides, wouldn't an xA be a more logical starting vehicle... same drivetrain and much more aerodynamic.
<cheap shot>

Ya... like that's difficult!

</cheap shot>

:rofl:
they actually are not much more aerodynamic as far as drag coeff goes........

The easiest or should I say cheapest, way to increase MPG is self discipline. I'm fixin to make a run up to Branson, Mo, Kansas City, and maybe Chicago and expect to average 36 to 38 MPG. Last time I went to KC I got just over 38.

[quote="Solarxb20"]what's funny is the xB's get better gas mileage on the highway with the air conditioner on and the windows up. The air coming in the windows drags the car down. I get 4 mpg better with the a/c on. problem is i like having the windows down. lol"

Hhmm. Four full mpgs! Wow! You should drive the highway with the a/c off, and the windows up. If you don't succumb to the heat you should get 43mpg :rofl:

I get SUPER good gas miliage. all I do is once a week drive around and find another scion and take the gas out from thier tank. See most scion owners dont have locking gas caps, so they are easy targets.


:rofl: LOL! hahhahaha, just jerking ya guys... the scion gets pretty good gas miliage I love it.

The big question is now, I bet all you are going to go get a locking gas cap now. LOL :rofl:

The gas tank flap is locked and released by a lever near the seat. Are you prying these doors open with a crow bar or something?

I wish my gas milage was better. I only get about 21mpg. I really only drive in the city tho and its only about 3 miles at a time. I have about an extra 100lbs of car audio equipment in my car tho that i listen to quite loudly wherever i am. I don't drive like an idiot tho, i'm easy on the gas. I was thinking of getting an intake to see if it helps any.

I wish my gas milage was better. I only get about 21mpg. I really only drive in the city tho and its only about 3 miles at a time. I have about an extra 100lbs of car audio equipment in my car tho that i listen to quite loudly wherever i am. I don't drive like an idiot tho, i'm easy on the gas. I was thinking of getting an intake to see if it helps any.
There MUST be someting wrong with your car- I'd go get it checked out....

Something else I thought of...

Lowering a car should increase mpg. The less air that's bouncing around under a car=less drag.

I suppose an air dam or ground effects to get that front bumper real low would help.

i'm so glad I got rid of the Z28 for my xb, now instead of filling up once a day, im filling up once a week on avg. :bow:

Something else I thought of...

Lowering a car should increase mpg. The less air that's bouncing around under a car=less drag.



Maybe... aerodynamics are notoriously counter-intuitive sometimes. One thing with lowering is that you would want to make sure the ride isn't any stiffer/harsher - every time you hit a bump, it slows the car down slightly, whereas if the car glides over the bumps it keeps its momentum with less effort and the car gets better mileage. So really what I said about rock-hard tires above (for less rolling resistance) has to be counter-acted by a smooth and forgiving suspension. (which lowered generally isn't.)


Also, whoever it was asking about the ground wires, that is a subject of a lot of controversy. Most people that do it report no change in performance (or mileage), some say it "smoothes out" their idle or the car's shifting and makes the car run a little better. Since there's no benefit in quarter-mile timeslips, I don't see the point for performance, and if there's no power boost I don't see how it would help mileage either. ( UNLESS you already had a bad ground to begin with.)

The bit about the ground wire kit had to do with response(for me).
Prior to having it, there was a pause at take off. Now with the kit , the pause is gone.. so I'm not mashing down on the gas waiting for it to go. A majority of my driving is in the city. Loads of stop n go. hence the improvement in my gas mileage.

what's funny is the xB's get better gas mileage on the highway with the air conditioner on and the windows up. The air coming in the windows drags the car down. I get 4 mpg better with the a/c on. problem is i like having the windows down. lol

btw.. i get 39 on the highway (I drive normal) and 32 in town.

I was just going to say something along these lines. We went to CA this weekend and I noticed that I used the same amount of gas coming home as I did going. Going I had air on and coming I did not just to see...nope the needle is in the same place now that it was when I arrived at my destination Friday. I thought it must be the windows down and wind thing.

:)

All the way to LA on one tank!!! Can't beat it! {Which is 260 miles with the back packed to the roof and three kids with the air on} Let me mention there is A LOT of up hill down hill driving going on between these two places esp thru the high desert and mountain pass area! lol

[quote="LVScionGal
I was just going to say something along these lines. We went to CA this weekend and I noticed that I used the same amount of gas coming home as I did going. Going I had air on and coming I did not just to see...nope the needle is in the same place now that it was when I arrived at my destination Friday. I thought it must be the windows down and wind thing.

:)[/quote]

Certainly not the 'best' way to check mileage. If I used that technique, the first 80+ miles on any given tank I could say mine uses NO gas. :silly:
I don't know about the window down thing, but MY xB definitely has been getting better gas mileage with the a/c off. Now, is that because of the a/c sucking power - or does it have more to do with the air temperature. When it is hot and humid - and the a/c is running full time - 35-36mpg. Last three tanks with the it less hot - and the a/c running part time - 38-39+

You can go 80 miles without your gas gauge moving? After i go 80 miles my gas gauge hovers bewteen 1/2 and 3/4

You can go 80 miles without your gas gauge moving? After i go 80 miles my gas gauge hovers bewteen 1/2 and 3/4

Yes Sir! But I FILL IT TO THE RIM (remember the old coffee commercial?). Aparently the filler neck holds quite a bit. Because - you can almost literally watch it free fall after that.
I TOP IT OFF for two reasons - 1. I want an accurate mpg reading, and 2. I drive on average 175 miles per day.
If I didn't get it FULL I'd have to fill it every single day. I live on a border state with PA having a little less gas tax when compared to NY - so I try to get back across the border before buying. Plus it gives TheWife and I an excuse to run to town - maybe an icecream sundae????
The only problem with that is, little time is left for driving the REATTA.

I get poor gas milage because I live in a crowded, conjested city. But even so, with all of this going on I usualy get 27 to 28 mpg in pure city mode in my auto xB. Big city traffic jams eat up gas! My T100 with V-6 auto gets around 16.5mpg in pure city mode. I live 7 miles from work and on bad days it takes 30 to 40 minutes to get to work. On usual days it takes 15 minutes.


05 camo xB

I have a Toyota Tacoma with 33" tires. It gets horriable gas mileage. So I usually drive my xB. Next year I might buy a Honda Ruckus moped to drive around town. When ever I'm filling up my xB everyone is jellous.

I can't complain, I have an automatic and I average between 32-35 mpg and I drive 90% highway including hills everyday. My last car averaged 12 mpg, which is why I don't own it anymore.

Trying something I read about Acetone. 2 oz per 10 gal. Been using it past 4 weeks and slowly uping now at 3 oz. My city driving is just past 31 mpg now and the bum-meter says its performing better.

Acetone is a bad idea. It will degrade plastics and synthetic rubber. I.E., your fuel line, gaskets and seals. It can also screw up your O2 antipollution sensor, which is very expensive to replace. It will take the paint off your car if you spill some on the side.

Please guys, don't screw up your already fuel-efficient new Scions with this urban legend.

Yes Sir! But I FILL IT TO THE RIM (remember the old coffee commercial?). Aparently the filler neck holds quite a bit. Because - you can almost literally watch it free fall after that.
I TOP IT OFF for two reasons - 1. I want an accurate mpg reading, and 2. I drive on average 175 miles per day.

If you're driving 175 miles a day its probably not an issue, but you should be careful not to flood the charcoal canister. If you top off the car on a cold morning and then don't drive it very far right away, and if it warms up during the day, the thermal expansion can cause liquid gasoline (instead of vapors only) to flood the charcoal canister. Its not the most expensive repair, but it is a hassle to have to take the car in for a fix.

Also, by topping off the tank you're causing ozone pollution to be worse by displacing the gas vapors into the air and not giving the charcoal canister a chance to do its job.

Best bet is to stop filling when the automatic shut-off on the pump clicks the first time.

Yes Sir! But I FILL IT TO THE RIM (remember the old coffee commercial?). Aparently the filler neck holds quite a bit. Because - you can almost literally watch it free fall after that.
I TOP IT OFF for two reasons - 1. I want an accurate mpg reading, and 2. I drive on average 175 miles per day.

If you're driving 175 miles a day its probably not an issue, but you should be careful not to flood the charcoal canister. If you top off the car on a cold morning and then don't drive it very far right away, and if it warms up during the day, the thermal expansion can cause liquid gasoline (instead of vapors only) to flood the charcoal canister. Its not the most expensive repair, but it is a hassle to have to take the car in for a fix.

Also, by topping off the tank you're causing ozone pollution to be worse by displacing the gas vapors into the air and not giving the charcoal canister a chance to do its job.

Best bet is to stop filling when the automatic shut-off on the pump clicks the first time.

My minimum drive after filling up is 6 miles.
If I did as suggested - stopping the fill up after the first pump shut off - I'd pump gas daily. Also, I would be guilty (like so many) of reporting inacurate mpg. That's not my style :P
Ozone pollution? - I probably caused the devestation of Katrina :loser:

What is the -emptiest- you've run your xB tank down before a fill up?

-I made error by delaying to refuel long after the yellow light turned on.
The car seemed to burp to remind me how very low it'd got. Might've been my imagination, though, 'cos it was subtle.

At the gas station I filled until the nozzle clicked off. I did not force in more fuel.

12.06 gallons ( I forget the official cap. of the tank but this is what it took from that pump)


====
humor idea for an xB rear window sticker:

If Hummer had a conscience
Scion xB would be it
-31/35 miles per gallon-

At the gas station I filled until the nozzle clicked off. I did not force in more fuel.

12.06 gallons ( I forget the official cap. of the tank but this is what it took from that pump)


You got 12.06 gallons into an 11.9 gallon tank.

Impressive.

:P :P :P but that's the fact, Max. If we consider the possibility that the pump and the specs aren't perfectly accurate... then there we are .

I prolly had another cup to go. I burped as I u'd out of Denny's side street. I got scared. I ran on down US1 to the nearest station.


===humor to ignore:
:loser: Sci walks on waters and runs on fumes :nails:
LO! and when fumes grow too thin he annoys the it out of people until they fume. Then he runs on.


and on




and

on!

http://img94.exs.cx/img94/1448/aabounce5cy.gif
:rofl: :rofl:
:rofl: :rofl: :rofl:
:rofl: :rofl: :rofl: :rofl:

"Ozone pollution? - I probably caused the devestation of Katrina "

If you really don't care about the planet's health you should move to Mars.

:P :P :P but that's the fact, Max. If we consider the possibility that the pump and the specs aren't perfectly accurate... then there we are .


I know the reason for it is likely either pump being off, or perhaps being completely low and counting the filler neck in the 12.06, and I'm not calling you a liar. I am actually impressed. I've never put more than 10 gal. in.

'Round here the gas pumps at the stations are regularly tested for accuracy by the state. They pull in, fill a precision 'test receptical' with fuel and if the pump reads within 0.05 of a gallon of the amount delivered it gets a 'seal' plastered on it with the date of the test. (Test measurements are corrected by table to quantity at 60 degrees, etc.)

If it does NOT meet the accuracy requirements it is shut down and not allowed to pump for customers until it is retested and recertified.

The reason I wrote all that is to say that I suspect the pump was accurate was more accurate in what it delivered than the advertised capacity of the tank and it's associated plumbing... :)

I suspect the capacity of our tanks is "at least 11.9 gallons" rather than "precisely 11.900 gallons."

My old Toyota Land Crushers always held more than advertised...

Stations 'round here measure fuel delivered in thousandths of a gallon (my last fill-up was 7.464 gallons).

"Ozone pollution? - I probably caused the devestation of Katrina "

If you really don't care about the planet's health you should move to Mars.

I wonder :ponder: if 'topping off' the tank causes more environmental concerns than the emissions coming out the tailpipe :ponder:
You've really got me thinking. Just this evening I stopped at the end of my drive to pick up the day's mail.....I let the car idle for the entire time it took me to walk the 10 yards - open the box - retrieve the mail - and walk back to the car. Now I'm thinking I should have shut the car off for that. What do you think :?

For that short walk you were probably at an even match since most engines start a little rich and give off more pollution at start than at idle... :)

As to 'overfilling' the tank, most stations have underground tanks (Duh!) and the gasoline coming out of the ground is fairly cool - usually in the 60's.

On days where the outside temp is WARMER than that, the gasoline will expand appreciably in the tank as it warms up, with the overflow either going into the overflow cannister or out of the system entirely and into the air...

The fuel system in a vehicle NEEDS 'headroom' for this expansion...

Filling to the top of the filler neck is very poor practice.

For that short walk you were probably at an even match since most engines start a little rich and give off more pollution at start than at idle... :)

As to 'overfilling' the tank, most stations have underground tanks (Duh!) and the gasoline coming out of the ground is fairly cool - usually in the 60's.

On days where the outside temp is WARMER than that, the gasoline will expand appreciably in the tank as it warms up, with the overflow either going into the overflow cannister or out of the system entirely and into the air...

The fuel system in a vehicle NEEDS 'headroom' for this expansion...

Filling to the top of the filler neck is very poor practice.

Short Walk: Plus, it requires more fuel to start than to idle for that time :wink:
Top Off: I'm thinking I drive the expansion off pretty quickly. Even if I fill up at night I have a 6-7+ mile drive before parking (plus the mail). I would have thought I'd experienced the canister problem by now if I were going to. Figure one top off every 2nd or 3rd day for the last 23-24 years :lalala:

I'm getting 31. '05 5 sp 17" wheels. I drive very gentle, never going over 3000 rpm. 1200 miles on the odo. 90% city driving

I am getting about 3 traffic jams per tank. There was one coming home today. Poor SUV's just sucking that $$ down and going nowhere. Going home isn't bad because I have an alternate route that usualy isn't conjested. Going to work, there is no escape. In all 27 to 28 mpg pure city.

Keeping your RPM down is only part of it too. Throttle input greatly determins the amount of fuel and ignition timing given to the engine. I have an auto trans and I try to get it to shift at 2000rpm at each gear. I have to rbarely throttle it to get it to go, and I have gotten used to taking my time. Once I can get into OD everything is good.

Just remember that %throttle is just as important as RPM. You may not take your engine over 4000rpm, but if you are giving it more than 50% throttle you are using more gas than necessary.

I also get anywhere from 30-37mpg...depending on whether myself or my wife is driving.

I wonder if 'topping off' the tank causes more environmental concerns than the emissions coming out the tailpipe

It causes different pollution, kind of a matter of opinion of whether its "worse" or not. Unburned hydrocarbons lead to ozone pollution and water pollution, what comes out the tailpipe is (assuming your engine is tuned right) is mostly CO2. But by topping off the tank you're causing the ozone pollution AND the co2, if you don't top off its only the co2 pollution by driving. Assuming that your charcoal cannister (and all the other toxic parts of cars) are properly disposed of when it winds up in a junkyard.

I'm not one of these treehuggers that thinks people shouldn't drive at all, but I don't see why people shouldn't take reasonable steps.

And about turning off the engine for a quick stop, conventional wisdom is that with a fuel injected car it does not use more gas to start it and that you are better off turning it off each time. That's why the gas engine in hybrid cars shuts off every time the car comes to a stop, and starts up again when its time to go. I don't quite agree with Tomas' take on it because he's assuming a cold engine but I'd guess you're picking up the mail on your way home, not when leaving the house, which means that your engine is already warmed up and won't be running rich.

However, for a stop of less than a full minute or so, its not economicial wear out a starter motor in a conventional car that way, so its just as well to leave the engine running. Hybrids use the electric motor and a CVT to start the engine, and don't even have a conventional starter motor so they're an exception.

I wonder if 'topping off' the tank causes more environmental concerns than the emissions coming out the tailpipe

It causes different pollution, kind of a matter of opinion of whether its "worse" or not. Unburned hydrocarbons lead to ozone pollution and water pollution, what comes out the tailpipe is (assuming your engine is tuned right) is mostly CO2. But by topping off the tank you're causing the ozone pollution AND the co2, if you don't top off its only the co2 pollution by driving. Assuming that your charcoal cannister (and all the other toxic parts of cars) are properly disposed of when it winds up in a junkyard.

I'm not one of these treehuggers that thinks people shouldn't drive at all, but I don't see why people shouldn't take reasonable steps.

And about turning off the engine for a quick stop, conventional wisdom is that with a fuel injected car it does not use more gas to start it and that you are better off turning it off each time. That's why the gas engine in hybrid cars shuts off every time the car comes to a stop, and starts up again when its time to go. I don't quite agree with Tomas' take on it because he's assuming a cold engine but I'd guess you're picking up the mail on your way home, not when leaving the house, which means that your engine is already warmed up and won't be running rich.

However, for a stop of less than a full minute or so, its not economicial wear out a starter motor in a conventional car that way, so its just as well to leave the engine running. Hybrids use the electric motor and a CVT to start the engine, and don't even have a conventional starter motor so they're an exception.

Thank you for the reasoned response - and for adding the economic element to the equation. As a financially challenged individual, economics play in to most of my decisions. Including the one to purchase the xB. It makes economic sense for me to 'top off' the tank on each fill up. This because of living on a border state where the 'at the pump' taxes are not equal.
That said - how much specifically of the ozone depleting chemicals are released during, say the last 2 gallons of the fill up? Understandably more will be as I pull out - therefore removing the rubber protection - before conclusion of the transaction. I just have no data as to what effect this has.

how much specifically of the ozone depleting chemicals are released during, say the last 2 gallons of the fill up? Understandably more will be as I pull out - therefore removing the rubber protection - before conclusion of the transaction. I just have no data as to what effect this has.


Beats me - I've read that the effect is worsened by high ambient temperatures, so the advice is not to fill up in the hottest part of the day, but I've never heard an exact number as to how much it is.

Come to think of it, slight amounts are always going to seep out of cars gas tanks, even when the car is turned off, because of imperfect sealing. Maybe the better way to phrase the question is "how much does the charcoal cannister help?" Whatever gets past the charcoal cannister goes back into the intake manifold anyway.

I'd guesstimate that pretty much "2 gallons of gasoline vapor" (with no idea as to what concentration that vapor is, of course) are displaced during the last two gallons of filling up... exactly how much damage that does I don't know. But all that's not really the point. We know its toxic... its like saying, I'm only going to eat a little bit of poison, how much damage will it do?

Beats me.....

I'd guesstimate that pretty much "2 gallons of gasoline vapor" (with no idea as to what concentration that vapor is, of course) are displaced during the last two gallons of filling up... exactly how much damage that does I don't know. But all that's not really the point. We know its toxic... its like saying, I'm only going to eat a little bit of poison, how much damage will it do?

What shall I do about the first 8 gallons of every fill up????? :eyebrow:

I can tell you this .... My box has 27K miles on it. I recently took a trip to Ohio for Scion Exposed from NJ, one way was 445 miles. Most of the trip i was doing 75-85MPH with the AC on. I averaged 30 MPG. This includes driving through the mts. near Pittsburg .. running a 17" wheel .. Injen 1st gen intake and minimal added wieght from a speaker box in the rear. Oh, and i do drive like i stole it.

I think alot of my good engine functions are due to the propper break in. I wont get into it here, basically i followed the MotorMans theory. I now get great fuel mileage, and no audible ticking or sounds from under the hood.

I love the looks on peoples faces when i tell them that i get an average of 30MPG .. and there are others who get even higher. Most cant believe it, then hop up into their "employee discounted " SUVs and drive off.

I can tell you this .... My box has 27K miles on it. I recently took a trip to Ohio for Scion Exposed from NJ, one way was 445 miles. Most of the trip i was doing 75-85MPH with the AC on. I averaged 30 MPG. This includes driving through the mts. near Pittsburg .. running a 17" wheel .. Injen 1st gen intake and minimal added wieght from a speaker box in the rear. Oh, and i do drive like i stole it.

I think alot of my good engine functions are due to the propper break in. I wont get into it here, basically i followed the MotorMans theory. I now get great fuel mileage, and no audible ticking or sounds from under the hood.

I love the looks on peoples faces when i tell them that i get an average of 30MPG .. and there are others who get even higher. Most cant believe it, then hop up into their "employee discounted " SUVs and drive off.

I was a tad behind schedule for a meeting Friday morning. On the way to pick up my co-pilot I had the pleasure of some 'back-roads'. Boy are these cars (xB) fun to drive when picking up the pace a tad. I don't dare to do this often as the various NewYork traffic authorities, combined with their DMV, have an issue with my driving history. It'll be interesting to see what this tank nets for mpg. I'm a regular 38mpg guy - but usually 'stroke' it with a goal of 40. The next fill-up will be the best test so far. My fun on the backroads, quite a bit of 70+ mph, and the A/C running too.

What shall I do about the first 8 gallons of every fill up????? :eyebrow:

I thought for sure you were going to bust on me for the "inexact science" of all this.

For the first 8 gallons just make sure the gas pump handle is pushed all the way in and if it is the kind that has the rubber flange to have it reasonably well seated against the filler neck. The charcoal cannister will work at its best effectiveness then.
Just doing that and then stoping filling when it clicks off is the best practice, but as for filling it to the rim you're on your own I guess.