Okay... I'm all about fuel economy. My xD is going to be ready to pick up tomorrow or Friday. I understand that lowering the car can yield better fuel economy at highway speeds. However, I do not want a car that bottoms out on bumps or has a harsh ride. I drove a Golf TDI for six years that had about 2" less ground clearance than a stock xD and would not want to go any lower.

I don't really care about the look. I don't feel one way or the other. The only reason I would get the lowered springs is for fuel economy and/or if the handling is improved without making it too bumpy.

So... my questions are:

1) Are people noticing an improvement in fuel economy with TRD springs?
2) How much do the TRD springs really lower the car? Scion says 1-1½ inches. What's the true ground clearance after installing TRD springs?

Thanks in advance for any opinions!

I tried to post this twice in the "suspension & handling" forum, but it keeps posting here. Is a moderator moving it? I would think a question about springs would go in the "suspension" section.

Well, according to the specs, the xD has 6.5" of ground clearance and my Golf had 5.1" of ground clearance. So, if I go with the TRD springs, I should have about the same ground clearance as my Golf (assuming the 1-1½" drop is correct). For the sake of fuel economy... and it's only $250... I think I'm going to go for it.

At today's gas prices ($1.70), a 2 MPG improvement would pay off in less than 100,000 miles, or four years at the rate I drive. If (okay, WHEN) gas goes back up, it'll pay off even sooner. Oh, and apparently my car will look better, too.

i don't think that their would be a huge increase in mgp...and it won't be noticable.

Some people on the forum have reported a 2 MPG increase. MPG in the 30s is -low- for me... I'd love to be able to get it above 40 if possible. 1 or 2 MPG could make the difference.

you will not see an increase in fuel economy with lowering the car. you are not a race car, so trying to get better aero on a square car doesn't really work.

You will not get mpg higher than maybe 38, even 38 is iffy. I consistently get 30mpg in my area and I am on NF210s but I don't drive like a granny. If you were looking for a car that got around 40mpg you should've gotten a Fit or something similar.

When I dropped my car I didn't see that big of a difference in mpg honestly. Though it has gone down slightly, maybe 1-2mpg, because I am on 18s now instead of the 16s.

TRDs don't drop that low honestly, but it is noticeable just barely though.


Oh if a mod was moving it, there would be a line under the first post about it being moved from <blank> subforum to <blank> submforum by <mod name>.

no real point in postin because eveyrone basically said it, but ill chip in my "no" as well :) ive lowerd mine and can say that theres no difference in mpg. its all about how you drive, and tire pressure. regular maintenance and weight also play a role. if youre carrying big loads all the time obviously there'll be a bit of a drop. just stick to driving speed limit, and not revving the sh** out of it.

on a side note, where did you read about getting better mileage from lowering the car? please post any and all links to this claim

most spring companies actually claim that lowering your car gives you better fuel efficiency due to less drag which it gives by lowering your center of gravity. its just a tactic to get you to further consider buying THEIR springs instead of others who dont make the same claim.

if you want a noticeable amount you'll have to go with a steeper drop. TRD springs will not change it enough, but even so with the steepest possible drop you'll only get maybe 1 mpg extra out of it if that. bang for buck, your better off getting your ECU reconfigured for economy but i'm fairly certain that that would void your warranty.

personally i always drive 6-10+ miles over the speed limit, i do not take my time accelerating and i still get acceptable fuel economy. i'm not trying to be a dick either, i just get bored driving 45 mph all the time and taking like 15 seconds to go from 0-30 like everyone else around where i live.

i have a lower drop, im on DF's, and theres no way that even on coilovers youd get as much as a full mpg more from just lowering. there's too much that holds us back (even a full tank hinders our liittle cars).

in all honesty, your speed isnt as important as your acceleration, but my point was dont drive like youre trying to get somewhere in 10 seconds..lol at higher speeds, for longer distances, you get better mileage (hence the fact that highway mpg is greater....). just as long as you sustain that speed for longer periods of time and dont have to constantly slow it down and pick it back up..

You will not get mpg higher than maybe 38, even 38 is iffy. I consistently get 30mpg in my area and I am on NF210s but I don't drive like a granny. If you were looking for a car that got around 40mpg you should've gotten a Fit or something similar.
I hope to prove you wrong. I have gotten better MPG than the EPA numbers on every car I have owned. Using the new EPA numbers, my Golf was rated at 35/44. I NEVER got below 46 MPG unless I was towing a trailer. I usually got 50+ with regular diesel fuel. My best was 55 MPG (903 miles on one tank).

My fiancee has a 2000 Civic that is rated at 24/32 and I never get below 44 MPG. I have gotten as much as 39 MPG, but I haven't tried any serious hypermiling... plus it's an automatic.

It also has a lot to do with my commute. I have a ScanGauge, and it clearly shows that the average mileage increases with distance to a certain point. For instance, at 1 mile from my house, I was averaging about 25 MPG in the Golf. At 5 miles I was at 40 MPG. At 20 miles the average was up to 50 MPG. So, if you have a short commute, your mileage will suffer because the warm-up period is a significant amount of your drive. It wasn't too hard for me to get to work at 60+ MPG. Driving fast on the highway would kill that, though... and I have to drive up to PA almost every weekend, and that would bring my average way down. In town I could keep it up near 50 MPG unless there was a lot of stop and go.

you will not see an increase in fuel economy with lowering the car. you are not a race car, so trying to get better aero on a square car doesn't really work.
Lowering a car reduces drag under the vehicle by reducing the amount of air that passes under. This is a fact. The only thing I am wondering about is how much of a difference it will make.

A 1-2 MPG increase is fantastic! +2 MPG would make it worthwhile.

on a side note, where did you read about getting better mileage from lowering the car? please post any and all links to this claim
I'll try. The search function on this forum is terrible.

Unfortunately, most cars (Scion included) don't have the tech following that VW TDIs have. If there is a question, someone will test it in a wind tunnel, inspect parts under an electron microscope, or send various fluids off to labs for testing. I'm not exaggerating... that's the way TDI people are. Around here it's mostly, "well, the manual says _____." It's just going to take some getting used to on my part.

you will not see an increase in fuel economy with lowering the car. you are not a race car, so trying to get better aero on a square car doesn't really work.
Lowering a car reduces drag under the vehicle by reducing the amount of air that passes under. This is a fact. The only thing I am wondering about is how much of a difference it will make.

A 1-2 MPG increase is fantastic! +2 MPG would make it worthwhile.

sure, lowering a RACE specific car will reduce the amount of air that travels under it, but this is an economy car and if you are looking for fuel economy than you are not worried about going fast. since speed is not an issue, current speed limits in the united states will not yield an increase by lowering a square economy car 1". you are right about enthusiasts though, they truly care about doing the right thing to a car.

as i stated, its not much of a difference and i have calculated it based off my own driving. if this is true, no matter how you drive, your MPG shuold increase (even if its only slightly.) but there is just no way to get to 1mpg by simply lowering your car. but just because you lower your car and it decreases the drag coefficient, doesn't mean you can gain an easy 1mpg out of it, otherwise im sure cars would be engineered lower, to be more efficient for our "fuel conservation needs"

i have gotten 41 mpg driving so thats no myth...it was on highway, and if youre going to comment saying you dont believe me then by all means do it. i dont care lol.

i agree with you on the fact that distance can increase fuel efficiency, and this is also due in part to the fact that once your engine gets warmed up, then its actually up to its full potential. driving a mile isn't exactly enough to get your engine fully warmed up and operating smoothly, and if it is, then it just barely scrapes by, but then you turn the car off and youre back to square one lol.

Here's one reference to better MPGs from lowering:
And lowering the car doesn't make a noticable difference in the city, but from experience I've noted a 3 MPG increase on the highway after lowering mine on DF210s.
Quote is by DeathMachine in this thread: http://www.scionlife.com/forums/viewtopic.php?t=235439
Also in that thread was some info about the Ford Flex. Apparently there was a 0.015 drag coefficient reduction by lowering the car by about an inch.

I don't understand why people are so quick to knock down an idea. If you don't know, just say you don't know... or nothing at all. Armchair science isn't very helpful.

dont know if youre refering to me, but i did state that i have DF"s and have noticed no such increase in mpg. if i can see proof of it then id like to see what it is that im doing wrong so i can increase my mpg. im not trying to knock it down without proof, im just trying to reason out WHY lowering my car didnt provide much results

Unless you can support your MPG with actual numbers from tank ups, then I won't believe anyone till I see the numbers. Yes there are a few people who are higher than normal with their MPG amounts, but there is a LOT of fluctuations between owners on the numbers.

It could the gas in your area, it could be the amount of traffic, how you drive it (hypermiling ftl), rate of acceleration, etc. I know its definitely the stop'n'go traffic in my area that kills my mpg and also how I accelerate most of the time.

agreed. on top of the fact that, since our engines are all built to "such high standards" (not..) there is the possibility now that each engine is adjusted in less than equal standards. timing can be off, valve lash, machined surfaces can be different, etc. these also affect fuel consumption..

i have a lower drop, im on DF's, and theres no way that even on coilovers youd get as much as a full mpg more from just lowering. there's too much that holds us back (even a full tank hinders our liittle cars).

in all honesty, your speed isnt as important as your acceleration, but my point was dont drive like youre trying to get somewhere in 10 seconds..lol at higher speeds, for longer distances, you get better mileage (hence the fact that highway mpg is greater....). just as long as you sustain that speed for longer periods of time and dont have to constantly slow it down and pick it back up..

hence the determining factor of "if that much"

speed has nothing to do with mpg, its all rpms if you sustain 30 mph in 1st gear you will get terrible mileage, if you sustain 30 mph in second gear (some 3rd gears can take it as well) it will be much much better mpg. there you go, speed has nothing to do with mpg. high rpms = dumping more fuel into engine its that simple. and dont always knock aero, there is an artist that made a semi-truck concept that increased fuel economy by 63% without touching the engine.

i was talking about engine speeds (RPM) but i did word that poorly sry

nah its all good, just gotta keep you xD people sharp ;-) haha j/k

doesn't mean you can gain an easy 1mpg out of it, otherwise im sure cars would be engineered lower, to be more efficient for our "fuel conservation needs"
Car companies make all sorts of decisions when designing a car. If MPG was their main concern, there would be a lot of different-looking cars on the market. I love hatchbacks, but a flat back induces a lot of drag. A rear that goes to more of a cone shape is much better for fuel economy. Why don't they do it? Because that is not a popular look.
speed has nothing to do with mpg
You don't have a ScanGauge, do you? More speed = more drag. More drag = more fuel needed to maintain speed. A car that requires 10 HP to maintain 50 MPH will require approx. 80 HP to maintain 100 MPH. This is regardless of RPMs.

Now, I can tell you from my experience that gasoline engines use a lot more fuel to accelerate. My TDI would get 20+ MPG while I accelerated up to highway speed. At the same rate of acceleration, my fiancee's Honda Civic is getting more like 8-12 MPG until it gets up to speed. Stop and go traffic really kills your mileage on gas engines.

Sorry if I seem obsessed with MPG... I guess I am. A lot of people around here tend to scoff at a 1-2 MPG increase. It's fine if you don't care about fuel economy... but ½ a MPG here and 1 MPG there... pretty soon you are increasing fuel economy by 10% or more. You can look at that as the price of fuel going down by 10%. You could look at it as 10% more miles before you have to fill up. However you look at it, more MPG is a good thing.

I'm not blasting anyone for not caring about fuel economy, or just being more interested in other aspects of car ownership. Fuel economy is important to me... especially since I am taking such a big drop in fuel economy by going to an xD. I want to keep my mileage up as high as possible.

You can bet that I will keep you all updated on my MPG numbers once I get a few tanks under my belt. I will be truthful about the numbers... I see no reason to lie about it. After all, forums like this are all about learning from each other... be it about audio systems, wheels, horsepower, fuel economy, or just sharing pics of hot chicks next to Scions... especially the last one.

its no problem to be obsessed with MPG, but it does seem like youre fighting a little hard against the facts that everyone brings up which disproves your question. sry if that seems harsh. i understand where youre coming from, we all wish fuel efficiency would be better, and that it wouldnt be such a problem today...keep us up to date, my findings for city driving are 26.9mpg and ive topped at 41.3 mpg highway...just to give you a ball park in numbers, and this is post drop.

speed has nothing to do with mpg
You don't have a ScanGauge, do you? More speed = more drag. More drag = more fuel needed to maintain speed. A car that requires 10 HP to maintain 50 MPH will require approx. 80 HP to maintain 100 MPH. This is regardless of RPMs.

Now, I can tell you from my experience that gasoline engines use a lot more fuel to accelerate. My TDI would get 20+ MPG while I accelerated up to highway speed. At the same rate of acceleration, my fiancee's Honda Civic is getting more like 8-12 MPG until it gets up to speed. Stop and go traffic really kills your mileage on gas engines.[/quote]

imagine drag as a steep hill, it takes more rpms to keep going against gravity, gravity = wind thus rpms = mpg

i really don't care about mpg to be honest, haha :-)

i should slap you for your comment about keeping me sharp....im as sharp as a diamond toothed saw blade son!!!

lol jk jk

^ :rofl: haha nice

imagine drag as a steep hill, it takes more rpms to keep going against gravity, gravity = wind thus rpms = mpg

Ummm... maybe in an automatic without the torque converter locked up... but in a manual trans, the RPMs will stay the same so long as the speed remains the same. When going up a hill, for instance, you might need more fuel (pushing the pedal down more), but the RPMs won't change unless your speed changes.

Even when talking about different speeds -- if you had a geat that turned 3,000 RPM at 50 MPH and a higher gear that turned 3,000 RPM at 100 MPH, it would still take a LOT more fuel to go 100 MPH. Same engine RPM, more fuel needed.

It takes about 8 times the horsepower to double your speed. Wind resistance is cubed as velocity doubles. However, as velocity doubles, the time it takes to produce the same work gets cut in half. 8 times the power is needed to cover the same distance.

although its the same RPM and more gasoline is being used, the point is if you rev even harder (getting into 5k) youre using even more fuel than you would be at 3k in a higher gear regardless of the resistance put up by friction/wind draft/etc.

I know what you are saying, but it isn't so simple. For instance, if you are going down a hill at 5k RPM you may be using less fuel than going up a hill at 3k RPM. It's all about the load.

yes..i know that. lol lets see what your numbers are after a few weeks. post em up and we'll see how they compare to some of the other numbers that have been posted up here

I have not been around much lately so I just saw this topic.
As for lowering improving mileage on the xD, I don't know as I have not lowered mine yet. I did notice an increase on my 2 previous cars though after I lowered them, but they weren't quite as boxy as the xD.
I have however noticed an increase in mileage with my aftermarket wheels, and my exhaust.
When I got my wheels I was specifically looking for something that would weigh less than stock. I ended up getting 16" konig britlites that weigh about 15 lbs each. The wheels increased my mileage about 1-2 mpg average.
A few months later I had the exhaust done from the stock resonator back with 2.25" pipe and a magnaflow muffler. I was expecting at best a 1 mpg gain, but was surprised with an approximately 3 mpg avg increase.
I have kept track of mileage since I got the car in September of 07, and I am currently at about 41,000 miles so I've run a few tanks through it.
When I got the car bone stock I would average about 32 mpg. With the exhaust and aftermarket wheels on I average about 37-38 mpg. Now that it is winter I have the snow tires and stock steelies back on the car and am only getting about 34 mpg average. With a lifetime avg of 34 mpg.

My car is a manual trans.
I keep track of my mileage at www.fueleconomy.gov if any one wants to know.
And I don't drive like I did when I was 18 anymore, which probably helps more than anything else.

but it does seem like youre fighting a little hard against the facts that everyone brings up which disproves your question.
There is a difference between facts and opinions. I appreciate opinions... but not when someone just assumes they are right because they have a gut feeling.

libima, nice to know about the wheels and exhaust. I've got stock steelies on the car now... but just until the 16" alloy wheels arrive. I doubt the Scion alloys are as light as your, though.

By the way, my first tank was just a hair over 35 MPG (35 calculated, ~38 according to the display). That's with whatever gas the dealership put in it.

Since there are people here who have kept their steelies, i was wondering if anyone here knew how much they weighed? i am looking to replace mine and am looking for something lighter, but i don't know the weight of my steelies. many thanks in advance.

I think Garage1217(?) said the steelies are about 40lbs a piece with the tires on them.

You also realize that the first few tank ups are not going to be accurate for what you will be getting later on correct? Why get an xD if you were getting the mileage you wanted out of the TDI?

she brings up a very good point...

she brings up a very good point...

yes but there is bound to be a fact defying rebuttal shortly

Why get an xD if you were getting the mileage you wanted out of the TDI?
The TDI was getting up there in miles and wasn't as reliable as I would have liked. There are no other sensible diesel options in the US.

Ultimately, the actual MPG number is beside the point. I want all of my vehicles to get the best MPG they can get. I have a Sprinter van and I love it when it gets more than 23 MPG. I also have an RV and do everything I can to keep it over 10 MPG. I like to squeeze out as many miles as I can for each vehicle.

Sorry if I have stepped on some feet in this thread. That was not what I set out to do.

Why get an xD if you were getting the mileage you wanted out of the TDI?
The TDI was getting up there in miles and wasn't as reliable as I would have liked. There are no other sensible diesel options in the US.

Ultimately, the actual MPG number is beside the point. I want all of my vehicles to get the best MPG they can get. I have a Sprinter van and I love it when it gets more than 23 MPG. I also have an RV and do everything I can to keep it over 10 MPG. I like to squeeze out as many miles as I can for each vehicle.

Sorry if I have stepped on some feet in this thread. That was not what I set out to do.

nah i'm just messing with you, but you have been quite resistant to other opinions, i'm just glad you dont get all huffy like half the rest of the people on this site. if you want to improve mpgs I would just go with another avenue. you could try getting your ECU configured to be a little more mpg oriented.

Yeah, I had gotten a new program uploaded to my Golf's computer and it gives more HP and more MPG (well, if you keep your foot out of it). Gas engines are new to me. I've never owned one. I'm not used to the strict fuel/air ratio that gas engines have to maintain.

Don't get me wrong... I seem to be getting about 35 MPG in my xD, which I am happy with. I still like to tweak it a bit. I also like the car to be fun to drive. I do "get on it" from time to time.

I guess I get as excited about 1 more MPG as other guys do about 10 more horsepower.

Just got all the add-ons done at the dealership today. They told me the shocks/struts were on back order, so I dropped it off for the alloys and short shifter, but when I went to pick it up, they said the shocks had arrived early, so they did them and the springs, too!

I got to drive it about 100 miles afterward, because I had to drive to VA to pick up a Christmas gift for my fiancee... the ride is rougher, but I like the handling. I guess I'll get used to the harsh ride... or maybe it'll soften up a bit. Anyway, I don't know about the mileage because I was hauling butt around the beltway at 70-80 MPH (keeping up with traffic). The readout said about 35 MPH, so I was probably getting around 32.

The short shift kit is AWESOME! The wheels (16" alloys) look nice, too... but I'll have to see them in the daylight to truly appreciate them.

do you think that the ride is so rough partly do to the new shocks/struts? also how much better would you say that these upgrades?

i only ask because i'm contemplating doing shocks as well, but if there's not that great of inprovment they i might not.

new shocks/struts are going to make a stiffer ride, which, i guess, you can say will make it more uncomfortable. bumps will be more noticeable because the shocks/struts are more agressive, and keep a stiffer ride. handling wise, its a great improvement, but if youre looking for comfort then dont expect much

Yeah, the rough ride is due to the shocks, struts, and springs. I knew it would be a rougher ride... that's the trade-off for more aggressive handling. I also installed the TRD sway bar that I got from TRD Sparks last night. The car is more stable on the twisty back roads. I didn't have enough experience with just the shocks/springs to say how much stiffer it is with the sway bar... but I did have fun on the back roads this morning!

I think the ride softened up a bit... or my butt stiffened up a bit. It does make drinking my morning coffee a little more difficult, though. I'm on the fence as to whether I would do it again.

I have an xD with the TRD springs and really I get about 33mpg and if doing freeway the highest I got was 38. The only thing about the springs is that it makes for a very bumpy ride. I am actually thinking about taking my off.

I just took a 250 mile ride this weekend for the holidays... and I got about 34 MPG (37 on the display) at 65-70 MPH with hills. Hopefully that will improve with break-in. I've only got 1,400 miles on the car now. I know my TDI didn't get top fuel economy until I had well above 20,000 miles.

With a little local driving, the tank average is up to 35 MPG (38 on the display).

I just took a 250 mile ride this weekend for the holidays... and I got about 34 MPG (37 on the display) at 65-70 MPH with hills. Hopefully that will improve with break-in. I've only got 1,400 miles on the car now. I know my TDI didn't get top fuel economy until I had well above 20,000 miles.

With a little local driving, the tank average is up to 35 MPG (38 on the display).

Lol, that's because diesel engines are just being broken in at 20k. You said it was getting unreliable? Really? The engine was unreliable? Or was it the car, because VW/Audis are notorious for having random expensive problems especially with anything electric.

if the car becomes unreliable its because of some malfunction in the engine. obviously if theyre notorious for having "random expensive problems, especially electrical" if theres electrical problems the first thing you should check is your battery, secondly, your alternator, because thats whats used to recharge your electrical system. both are part of the entire "engine" system.

VW/Audis are notorious for having random expensive problems especially with anything electric.
Yeah, exactly.

TDI engines are awesome pieces of equipment... there's no doubt about that. Like a lot of Audi/VW systems, they lose sensors and other electronic parts like crazy. There are a few potential BIG problems with TDI engines... and they are:

1) Timing belt. Most TDI engines meet their maker because of a lapsed timing belt interval, a botched TB job, or simply a failed water pump, tensioner, or roller. Any of these will cause a $3,000 to $6,000 repair bill. The TB job requires a whole set of special tools and a computer hookup to be done right. I have done a handful of them and they are no fun. I stopped doing them because of the risk of failure.

2) Injection pump. The older Bosch VE rotary pumps were not too bad, but they eventually fail like any mechanical part. A used one can be obtained for around $900 or a new one for $2,000. The install requires about 6-7 hours and includes a full timing belt job. See #1 about that. The slightly newer Pumpe Duse (unit injector) systems are even more expensive to repair and require a special type of motor oil that isn;t even available in stores. See #4 below.

3) Charge pressure system. The turbochargers rarely fail themselves, even though they spin at upwards of 280,000 RPM and regularly see boost levels of 18 PSI or more. However, there are numerous other mechanical and electronic systems in play here. The older a TDI gets, the more time it spends in "limp mode" with no boost because something in the system isn't working properly.

4) Oil. The older TDIs had relatively loose oil requirements -- synthetic 5w40 oil approved for diesel engines. The Pumpe Duse systems require VW 505.01 approved oil to protect the cam-driven injector system. The camshaft actuates rockers that drive the injectors, which produce nearly 30,000 PSI of pressure. Failure to use the proper oil will cause premature failure of the PD system, which will cost thousands to repair. Most VW dealerships actively remove all warnings about the oil requirement (including a tag hanging from the rearview mirror) and do not even carry the proper oil for use or sale. Many of the 2004-2006 TDIs will die an early death because of this.

After reading this post at length, I wanted to chime in with a couple of reason why lowering a car DOES increase fuel efficiency.

As mentioned, you are reducing the amount of air traveling under your vehicle. That does not sound significant, but the air trapped under your car is turbulent since very few cars currently come equipped with smooth underpans, like the new Prius.

Secondly; by reducing the gap between your tire and the fender well, you are also cutting back the turbulent air formed by the turning wheel. Picture a car in the rain and look at the mist coming from the inner fender, then notice one on a lowered car. More air is forced down and not out into the air stream.

Lastly and most important, most of you do not see increases in FE because of your perception of performance from such a mod. You lower your car, ergo you drive faster, corner harder, negating any benefits from the mod in that sense.

This is why on high mileage vehicles you see front and rear wheel skirts. These skirts divert air under the car instead of into the air stream preventing turbulence and thus drag.