What size are the factory 2008 16" alloy wheels?
16x7 or 16x6.5?
Backspace at 42mm?
What's the hub bore size?
I believe the bolt pattern is 5 x 114 mm...

I was wondering if it'd be worth it to buy some ligher-weight wheels, maybe forged aluminum for use in summer, and sell my factory 16" alloys.

I believe the factory alloys weigh about 19 lbs and I've seen several wheels at 16x7 and 5x114 that are between 12-15 lbs.

I would like lighter wheels for both improved ride quality and a slight power "increase." I found a site that does horsepower calculations and figured out that dropping 5 lbs of wheel & tire could feel like either adding 5 hp to the r18 motor (?) or dropping 80 lbs of sprung weight.

The factory rims look very nice, but I don't like how "portly" they are.

 

16x6.5 +42 i believe. hub bore is 64.1. bolt pattern is 5x114.

look into 17's too. going to a lighter wheel is always a good idea. my personal favorite are rpf1's but there are a lot of choices. picking out a good tire is also important too.

your "power increase" is off. you will notice a "power increase" but not by that much. it is more like 10lbs to every 1hp.

 

Thanks.

For the moment, I prefer the idea of 16's for slightly less weight and typically narrower footprint (205R/55 vs. 215R/45) for the "underpowered" R18. However, I was stunned when I bought 195/65R-15's for snow tires that there was a dramatic difference in sidewall flex, and the 15's felt almost twice as "squishy." Is there also a huge difference between the handling (flex) of 215/45R-17's vs. 205/55R-16's?


A little off topic, but half the reason I'd like to do this is for the minor power & economy increase. But I was wondering would a cold-air kit make more difference power-wise than the lighter wheels, at half the price or less? My scan gauge II shows that the inlet temp from the factory is usually only 15 F warmer than ambient at cruise, so for a cold air kit to make more power, the main perk should be more airflow rather than just cooler air.

 

sorry...honestly dont know how to answer your tire question.

i dont think intakes do much (i have one). i got a really good price for it that is the only reason i have it. i personally have always felt more of a difference with lighter rims than with an intake.

 

No problem, just curious if you or someone else had gone from 16" to 17" rims with the stock tire size and noticed a difference. (I suppose I could go test-drive an Si and I could probably find most of the difference, besides the Si's 20% increase in spring rate)

So you've bought lighter wheels?
How much lighter were they than what you had before?