05 XB. Looking at a little more ummph, but don't want to lose the mpgs.

I have searched around and it appears that the K&N is a good choice.


Who's has a Cold Air Intake (only, without other mods), and is it worth it? What was the gain? Did your MPGs changes?

Thanks!

 

sorry for bumping this but doesnt seem like anyone is helping


As for the CAI and mpg, anytime you modify the hp gain or anything like that you will lost mpg but with this i dont think you will lose a noticable change


just switch to a K&N and smile though a CAI sounds better

 

Don't bother with a CAI. Convert your stock airbox into one. Buy the K&N drop in filter. Remove the stock snorkel and get some 3 inch aluminum flex tubing at lowes or home depot and a 3 inch worm clamp and route it between the batt. and coresupport over into the void behind the headlight and fasten it to something and there you go all the function af the CAI for about 60 bucks

 

I got the Injen 2 piece CAI only. about 40 mpg avg. Umph is about 4000 rpm. In my opinion, it was worth it. I used to do ghetto mods when i was broke. you save alot of money, but don't get the same quality, wow factor, and output.
just depends on you want.

 

i just put my ingen cold air on tonight. i can't wait to see if it changes mileage or not. i only have 650 miles though so my mileage still hasn't gotten to the sticker estimates.

 

And driving around on the hills of York,PA you never will get good mileage. I hit 36 MPG once driving through OH on I-75 where it is flat as a pancake LOL

 

I've got to have something wrong with my xb then. I have 19" wheels and a AEM CAI and am only getting like 23-24 mpg. Does anyone have any ideas what might be wrong?

 

mpg is more a factor of engine design and driving habits... exhaust and intake mods will make VERY VERY SUBTLE differences in the MPG... to get the best gas mileage you should:
#1... driver slower
#2... accelerate slower
#3... roll windows up
#4... turn a/c off
#5... coast more, brake less
#6... lighten the load
#7... proper air pressure in tires (this is in the manual, not on the tire)

exotic ideas...
#8... remove rear view mirrors
#9... cover rear wheel wells
etc.... you get the idea...

I get 32mpg in the city (under 50mph) in Denver... I get 28 or 29 on Interstate... I have a roof rack and it has skis and snowboards on the interstate...

Xbnall... the reasoning behind your poor mileage is most definitely due to your driving style... short high revving trips will be worst, long slow steady drives will be best... octane will never make a difference, 400lbs of passengers or stereo equipment will always lower the mileage...

 

Rolling with 19's gives you far greater diameter then stock... Use more power/gas to get rolling from start. Just like starting off in 2nd gear. Should get better mph at higher speeds though.

 

From: jethro b
To: turtles808
Posted: Tue Nov 16, 2004 6:27 pm
Subject: CAI
My mod on the factory air box does the same exact thing the pricey CAI do. The ONLY difference is the BLING factor, Mine is more sleeper than bling bling. The throttle body bore is the weak link in the intake system. With the K&N filter and larger air intake there is no difference in airflow between the stock box and a CAI. FACT! PS not everyone wants to spend $$$ on parts that really do little.


1) I'm sure his mod does EXACTLY what a dyno proven one does so box it and sell it.
2) More sleeper... I usually drive around with my hood down.
3) No difference in airflow between stock... why bother wasting you precious $60.

Sorry, but this reply is because it just irratated me that it was a stealth attack at me through the PM. I never attacked anyone but just gave my opinion. This if FACT.

 

I'm not in agreement with you on the idea that 19" rims will lower your mileage. Work is work, gear ratios do not affect your mileage, your rate of acceleration does. Now the torque to the ground will be lower, so acceleration will always be lower with the same engine if you go to plus size wheels, but that is a sacrifice he took on willingly - he chose asthetics over performance. Any SCCA or Autocross racer will tell you that smaller diameters is better for performance (gearing wise)... but if there was any correlation between mileage and wheel diameter it would be in the automakers best interest to decrease rim sizing.

work is equal to force over a distance... there is nothing to do with gearing. this distance is the forward motion.

 

Larger wheels will indeed affect your mileage as you have to overcome more resistance at every start. Work is indeed equal to force over distance so larger wheels with higher weight and more importantly the weight of the tire farther away from the center of the wheel will cause your engine to have to do more work to accelerate. In addition, the additional rolling resistance of a fatter tire will increase friction and decrease overall mileage. The amount of effect that these factors have is difficult to quantify but they will indeed have an effect. An aggressive driving style will exacerbate these effects.

 

Yeah maybe. Just seems kinda outrageous. Do you guys think that my local dealer could maybe do some sort of diagnostic test or something?

 

[quote="turtles808"]From: jethro b
To: turtles808
Posted: Tue Nov 16, 2004 6:27 pm
Subject: CAI
My mod on the factory air box does the same exact thing the pricey CAI do. The ONLY difference is the BLING factor, Mine is more sleeper than bling bling. The throttle body bore is the weak link in the intake system. With the K&N filter and larger air intake there is no difference in airflow between the stock box and a CAI. FACT! PS not everyone wants to spend $$$ on parts that really do little.


1) I'm sure his mod does EXACTLY what a dyno proven one does so box it and sell it.
2) More sleeper... I usually drive around with my hood down.
3) No difference in airflow between stock... why bother wasting you precious $60.

turtles808 you really need to read the stuff before you post.
1-there's nothing to sell it involves a k&n filter a clamp and a piece of flex tubing???
2-never said you drove with hood open just at shows... bling bling
3I wrote no difference between my MODDED stock box and a CAI... READ CAREFULLY AND UNDERSTAND WHAT YOU READ BEFORE POSTING YOU WILL LOOK MORE INTELLIGENT

 

How much performance he is still trying to get may be part of the problem. Is he still trying to drive the same speed he would with stock wheels, or is he saying "I've got bigger wheels, so understandably, I'm not going to go as fast and therefore won't try and give it as much gas to move me like before.

The only test they would probably do is have someone drive it carefully and see what the mileage comes out to. If there was a problem with your engine that was using too much fuel, you'd probably throw a CEL.

The tests are done by the EPA for comparison values ONLY. Toyota MUST use those numbers, but they don't guarantee them. It's not an easy battle and they will likely highlight your wheels as an issue as well. I'd bet money it's the wheels...

 

so basically you're saying that you don't have a degree in engineering... or physics... not trying to be rude, but don't go against my statement unless you understand what you are talking about... you need facts to back it up...

work is defined as force over a distance... torque is defined as force AT a distance... you are confusing the two... hp is a measure of ability to do work, you need horsepower to travel fast, you need torque to accelerate fast... PERIOD

If he complained of slower acceleration you would be correct, but horsepower cannot be geared - ask anyone with a dyno..., a 19" rim will actually be more efficient at rolling when considering bearing friction (slower rpm for same speed)... you will pay the penalty for larger inertia which is controled by weight at a distance from rotation, so YES it will be slower, but NO you will not be less efficient...

I AM a mechanical engineer, I have worked with rotating equipment and have ZERO question about this topic... I have hours and hours of course work, I have hours and hours of application...

 

So if the "slower" was countered by giving it more throttle, wouldn't that equate to less eficiency?

Does that make sense?

Maybe another example:

If it takes 10 seconds from point A to B with stock wheels and
If it takes 12 seconds from point A to B aftermarkets,

then if he's driving it hard enough to still make the trip in 10 seconds with the aftermarket wheels, wouldn't that eat more gas?

 

SO in a nutshell the larger-heavier wheels hurt performance and mileage. YES???

 

So basically you are saying that you are a mechanical engineer and yet you willfully insult people who are not without really thinking about your statements.
Horespower and torque are the same thing, horesepower is a measure of torque over time. In fact the formula for horsepower is Torque X RPM / 5252.
I may have mixed my definitions of horespower and torque a bit and I appreciate the correction, but the results still may vary.

Now granted in practice depending on gearing, an engine that produces more torque at low rpm may accellerate a car faster, but gearing makes a huge difference in this equation. A good practical example of this is early formula 1 engines that produced their power at very high RPM and therefore produced very little torque, but still managed to accelerate very fast.
Bearing friction is a miniscule effect compared to the rolling resistance of tires on the road. Overcoming the initial intertia that you very accurately described and continiung to overcome it at any stop light, will contribute to poor fuel econnomy, in addition, an engine that produces little torque at low RPM such as the XB this effect will be even greater.

Now aside from our bickering, without doing a lot of calculation which you are probably more qualified to do than I, figuring out just how much of an effect this is would be difficult. I will stipulate that the driving style of any individual and other factors such as temperature, AC operation etc, probably have a greater effect on fuel mileage than large wheels, but to deny that they have any effect just not correct.

 

whoa nelly... back it up...

torque and horsepower are absolutely not "the same thing" and they are correlated by RPM not time... PERIOD...

I am not trying to be insulting, but I am giving some credentials to say that I have an understanding of the topic, and I am not just speaking my opinion...

ok... so questions answered and facts corrected as I see them coming down the pipe... here we go...
#1... thescionicman... you mention getting worse gas mileage from changing two things.. one is wheel size and throttle position... YES to overcome the inertia and accelerate faster you will always sacrifice gas mileage, but that is not what is killing his mileage... he made a choice... he picks asthetics over sound engineering design... putting a spoiler on your car will take away mileage period... accelerating harder will have the same affect... mileage on the highway is at constant velocity AN INCREASE IN ROTATING MASS DOES NOT HAVE ANY MORE EFFECT ON MPG THAN ADDING A SANDBAG TO YOUR CAR, so if the stock wheels were lighter in total weight then YES mileage will suffer, but this is not often the case and it is by no means the rule, many aftermarket wheels are lighter than stock steel wheels with stock tires...

#2.... jethro asks if it will hurt... no, if the weight of the wheels is the same and the driver gives the same throttle tip in as he did prior, then no... but this is only the case for acceleration, on the highway he will have EXACTLY THE SAME MILEAGE unless he went wider or is running too low an air pressure...

#3.... turbosnow... I am just the messenger, I'm the Alex Trebeck to this thread - I didn't invent the idea, I just studied it and I am holding the answer... don't shoot me, you are incorrect and yes it stings when you pull your foot out of your mouth... so take this oppurtunity to broaden your knowlege base, I am just trying to keep the message board from going to total crap because people spew opinion as if they had a PhD in the subject...

#4... a honda S2000 has 250hp and will top out at well over 150mph... but it has 150ft-lbs of torque... which is about the same as the tC... will they top out at the same speed?? the answer is NO... hp is what gives a car the ability to reach high speeds - to overcome the negative work (called drag)... the 1/4 miler is after torque... PERIOD...

#5... Formula 1 and CART/INDY cars still make their peak power near 18 and 19,000 rpms... they make about 900hp and about 150 or 175fl-lbs and they can break 240mph with the wings "tuned down"... horsepower makes this possible.. the reason their 0-60 is so quick is two fold... A-tires... and B-weight... gearing is always a factor, but gearing is used to put the engine in it's efficient range, we could have a two speed tranny in the box and it would still drive, but you'd have to bog it in both gears and rev until it was screaming for mercy... so we have more gears to help us keep the engine in the efficient range... indy cars are geared to have a gear range for MPG and also rev to the power range... the efficiency area is a RANGE, not a point, so slowing the engine down by 5% won't make it more efficient... at least not an amount you could perceive...

you cannot do bolt on to make better mileage... here's a rough story to help understand this point... take two identical cars, put a V-12 6.0L in one and a I-4 1.5L in the other... WHY will the four cylinder get better mileage?? because you will be FLOORING IT MORE... you don't have a "gas pedal" you have an "air throttle" and the more you push it, the more efficiently the engine can bring in air... so it creates less vacuum and makes more horsepower... this is referred to as volumetric efficiency and is the reasoning for dropping cylinders in the new Caddy's... the goal is to put the smallest engine in that can do the required task... so to get more MPG you need to have a lower potential horsepower and you need to use as much of that as possible... so the difference needs to be as small as possible... does this click??

inertia is the property of a body that wants it to stay at rest or stay in motion... it is avoiding change... so to get high inertia - build a dumbell... to get low inertia - build a bowling ball or a shotput... inertia is the relationship between the point of rotation and the point where the mass is located... so YES for a 19" rim you will have more inertia to overcome... but more effects will be stacked upon you for the reduction in gearing...

I am not trying to flame, I am trying to set the record straight... please ask questions, i will check here as long as I get flags in my email...