Hey everybody, just curious if anyone knows (or knows how to calculate) what size rim would net you the best fuel economy, particularly if you do a lot of highway driving. I know changing rim sizes can have an effect. I also would like to know how big of an impact this could actually make on mpg....and get some recommendations on the lighter rims i could buy (not looking for anything pretty, just lightweight and strong. it can be purple for all i care)

btw car is a stock 4-lug 4G Si 4ws


Modified by monalisa overdrive at 7:43 AM 11/15/2004

 

20's.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by hoehouseworker &raquo;</TD></TR><TR><TD CLASS="quote">20's. </TD></TR></TABLE>

**** that y0!

24 1/2 inches

 

For strictly highway driving, heavier/bigger rims will help fuel mileage.

 

Yeah, lighter rims require less effort to accelerate, but lack inertia, so the engine has to keep pushing them a little bit more to maintain a certain speed. They will help you to accelerate faster, though.

Of course, heavier rims would be the opposite: harder to get moving, but once they are moving, it requires less effort to maintain a certain speed. They will make you accelerate slower.

Size will affect accelaration, but I don't see how it will affect MPG other changing how the car sees the wieght, for example: a 20" wheel of the same wieght of a 14" wheel will seem much heavier to the car because the wieght is farther away from the center of rotation.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Hawkze_2.3 &raquo;</TD></TR><TR><TD CLASS="quote">Yeah, lighter rims require less effort to accelerate, but lack inertia, so the engine has to keep pushing them a little bit more to maintain a certain speed. They will help you to accelerate faster, though.

Of course, heavier rims would be the opposite: harder to get moving, but once they are moving, it requires less effort to maintain a certain speed. They will make you accelerate slower.

Size will affect accelaration, but I don't see how it will affect MPG other changing how the car sees the wieght, for example: a 20" wheel of the same wieght of a 14" wheel will seem much heavier to the car because the wieght is farther away from the center of rotation.</TD></TR></TABLE>

sort of..

wheels are the last part of the final drive. bigger rolling circumference equates to a higher mph at a lessor rpm, which saves gas.... big rims save gas b/c it lets you cruise at a higher mph with less revs.

 

You also need to take into account the tire size. A narrower tire has less resistance on the pavement. I know some economy cars used to come with low resistance tires (e.g. narrow and hard) for better milage.

 

So you're willing to invest 3K on a wheel package, to save 20 bux on gas?

Seriously though, I dont think anything you do is gonna make a significant improvement. Just keep your car up to tune and it'll do its job.