Has anyone's modifications really resulted in MPG gains? Lightweight wheels? T1R intake or voltage stabilizer? K&N replacement filter? (I am not interested in running without a spare tire or driving on 50psi in my tires) I have seen claims about these things but nothing specific.

 

Of course they do. I can attest to the lightweight wheels and K&N replacement filter. When I switched from 35 lbs to 30 lbs wheel/tires I gained about 2-4 mpg and adding the K&N filter gave me about 2-3 mpg more. I may test a voltage stabilizer down the road, but my next thing is to get even lighter wheels/tires and getting better at driving to save gas.

 

i keep seeing 50/50 pos. and neg. feedback on the k+n filters. how they hurt the o2 sensor. how they dont mess up anything... whats the deal ? is a better one out ? mugen ? HKS ?

 

If you are paranoid about adding an aftermarket air filter to your car, maybe you should stick with the OEM filter. It's only 2-3 mpg and I am sure you can get that just be driving more gas efficiently.

 

[quote=claymore;140905]

Claymore speaks the truth (well, most of the time anyway- here for sure).

This is NOT to imply that Claymore intentionally lies in his posts. He is just as capable as any of us of being fooled by false information or temporary misconceptions.

 

Well, if you drop in a standard transmission...

What are your normal driving conditions? If it's mostly high speed highway, you would want to concentrate on aerodynamics since drag swamps other factors.

Probably a little. Slightly taller tires (e.g 185/60R15 or 195/60R15) might help 'fix' the short gearing. (You could pick a size that corrects for the odometer issue.) Low-rolling-resistance tires should help, but that information tends to be hard to find. Wide(r) tires hurt fuel economy.

I don't know anything about it. It probably depends mostly on whether it ends up increasing or decreasing typical intake temperatures. Serious mileage nuts build WAIs.

Probably won't help, but won't hurt.

I don't think anyone has done a controlled test with a Fit, but this person found no difference between filters.

50psi may be excessive (especially if your tires are rated 44psi) but go as high as you are comfortable with.

 

Regarding K & N Filters:

I started with the K & N drop-in and saw no increase in fuel economy. Then re-made the screwed-up new Typhoon intake so that it would actually fit under the hood. This intake system SHOULD have even less air flow resistance than the low-resistance drop-in. No measurable mileage increase with the Typhoon system.

Regarding over-inflating tires:

This may slightly lower rolling resistance by lessening tire contact area with the pavement, but it will also make the ride quality more jarring, lessen wet pavement traction, and cause accelerated wear of the center area of the tread.

 

I already have the K&N and am a long time user on all my cars. I am considering Helium wheels (11# each). I am wondering what else works. The reason I said 'not interested' in high PSI is bacause of safety--I need more grip than that! The T1R intake thread lists better MPG as a benefit. I am surprised that less restrictive exhaust does not improve MPG but I don't know how much racket I would be willing to put up with anyway.

 

Unless you're running vintage bias-ply tires, higher pressure won't increase center tread wear. (Underinflation does increase outside tread wear.)

This article claims increasing pressure improves cornering traction and decreases the risk of hydroplaning. It's reasonable to expect that there may be a decrease in braking traction from higher pressures (as there presumably would be from LRR tires, like the stock Dunlops), but most of the fuel economy improvement from tire pressure comes from reducing the energy lost to sidewall flex rather than road friction.

 

I added a Spoon filter and I'm seeing a 3mpg increase.

 

i'm not done yet with my mods but after i install my SCANGAUGE II it completely change my driving habits which help to increase my MPG,i'm getting 32-34 MPG,and i have AT

 

hey man, how did you mount your k&N drop in ??

I cant figure out whether to put the lipped edge facing up or down :S

most people mounted it lipped edge facing down so that's what I did. K&N insist that it mounts properly only one way and that the clips wont clip in the other way but I've triend both orientations and as far as I can tell it's the same

 

the IAT is the only sensor on our fits (which use MAPs) which could possibly be affected but since the amount of oil on the K&N is so small I can't believe that it would cause any damage at all (recommended 15ml of oil per service)

 

Modifying the pressure on the gas pedal can increase mpg...

ba-dum

 

I kinda eyeballed the factory one when it came out and tried to put it in like that. It does look like it would work fine either way. I think this was puzzled over in the K&N sticky thread.

 

no air filter is going to drastically change mpg. a spoon filter isnt going to add 4 mpg, if it did, honda woulda had it stock and advertised 36/42 epa on the sticker.

lighter wheels reduce weight, but it's not going to change your epa enough to make you notice.

even if u generously say 1lb of unsprung weight = 10 lbs, going down 4 lbs per wheel, 4 wheels, 16 lb of unsprung weight, 160 lb of curb weight.

the difference is going to be driving alone and driving with a passenger. when is the last time someone notice a gas mileage difference when you had a passenger??

there are no easy cheap mods that can all of a sudden give you much better gas mileage, if such a thing exist, it's already on the car.

 

Absolutely... with a qualification: there are tradeoffs between mileage and other factors.

As far as 'easy cheap mods' go, tire pressure is the classic example: ride comfort at 32psi, mileage at 42psi.

Likewise, there are things that can help under certain conditions that are useless or worse under other conditions. For instance, in the winter here I add a partial grille block to let the engine warm up a little faster. This won't much help someone in Arizona.

 

Does driving technique count as a modification

The only mod I did to my car (except driving tech...) is the KN filter. It took a long time for the filter to break in. I do notice the car gets faster. Mileage has gone up however, for mileage it is not a controlled experiment. My new job I drive a lot of highway, so it might be that and not necessarily the filter. My last two fillups were record breaking, 37 and 36mpg, so it's possible the filter (or even the engine) is still breaking in, cuz I am not driving any differently. I typically get 32-35 mpg for your reference.

 

This is my question about the voltage stabilizer. People are quite enthusiastic about them after they've got them installed but if a few bucks worth of capacitors really helped that much, wouldn't Honda just put them in at the factory?

 

What do you mean by 'long time to break in' on an air filter?