More wheel or More sidewall

leevining1 · Post by **leevining1** » 20 Apr 2009, 10:38

Hi, I just went thru the process of replacing the front tires on the '96 5cyl turbo wagon I bought some months ago. It came with P6's and I really was not appreciating the ride or handling as much as I wanted so out I went to replace them. I immedately ran into the arguement about do I want to go to 16 inch wheels or stay with the 15's. After much thought and discussion I opted to stay with the 15's because this allowed me more sidewall and to me, better ride and handling. I am not unhappy with my choice......I bought a pair of Dunlop Signatures 195 - 60 and like them alot. I had not realized how hard those P-6's were and unforgiving in the turns, these Dunnies suit me just fine. Are there anyother arguments for or against more sidewall or more wheel?

Leev

Post by **MadeInJapan** » 20 Apr 2009, 15:25

It's all preference- just make sure your tires stay inflated.

Post by **matthew1** » 20 Apr 2009, 16:18

^^^ good point, MIJ!

Typically, performance increases as the sidewall height decreases.

But your comfort increases as your sidewall increases (as your roads' potholes increase as your local government's road maintenance budget decreases

).

A taller sidewall is more able to absorb bumps.

Post by **tjts1** » 20 Apr 2009, 18:51

Our base 850 left the factory with a set of 15" steel wheels and unsightly hubcaps. So when I cam across a set of very cheap 16" turbo wheels on CL, I bought them. Boy was I wrong. The first thing I noticed when I put the wheels on the car was how much more throttle input it took to get the car moving from a dead stop. As if somebody had stuffed the airbox with pillows. The steering also felt heavier and less responsive, and ride quality deteriorated. Granted, the rear 16" tires were close to worn out but the fronts were nearly brand new. So what was going on?

Base 850 15" steel wheel minus hub cap 35 lb

850 16" turbo wheel 45.2 lb

40 lb of extra rotating mass makes a noticeable reduction in acceleration and ride quality. Sure 1/2" less rubber between the rim and the road might improve steering feel but is it worth the lost fuel economy, slower acceleration, deteriorated ride quality and more expensive tires? Not to me. Buy the best 15" tires that fit your budget goals.
cheers
Justin

P.S. Its amazing what you can do with some steel wool, rattle can and elbow grease. Next step is early 240DL aluminum center caps to cover the lugs.

leevining1 · Post by **leevining1** » 21 Apr 2009, 09:45

Matt, points well absorbed

But your comfort increases as your sidewall increases (as your roads' potholes increase as your local government's road maintenance budget decreases ).

A taller sidewall is more able to absorb bumps.
---------------------------------------------------------------------that is sure the case around here(socal) the potholes are just not getting fixed except around police and firestations. So steering response is more and more critical. I may have lost a bit of that but the bigger shoulders and taller tires more that make up for it.

BTW......what sort of K&N set-up do you have for your T5, or is it just the filter element??

leev

leevining1 · Post by **leevining1** » 21 Apr 2009, 09:52

tjts1: thanks for the feed-back, I had not considered the weight issue, I was thinking of the larger circumference, and the extra umph it takes getting that rolling. But the main reason I like the 15's is a more flexible sidewall, that is if the tread stays on the street

Post by **vegasjetskier** » 21 Apr 2009, 10:15

leevining1 wrote:tjts1: thanks for the feed-back, I had not considered the weight issue, I was thinking of the larger circumference, and the extra umph it takes getting that rolling. But the main reason I like the 15's is a more flexible sidewall, that is if the tread stays on the street

Usually when the wheel diameter is increased the tire "aspect ratio" is decreased to keep the overall diameter about the same. I.E. if you go from 15 to 16 inch wheels, you might decrease the aspect ratio from 70 to 60, going from 16 to 17 you might decrease it from 60 to 50, etc.

Typically a larger wheel, lower aspect ratio combo will give you better handling and a rougher ride. While the larger wheels might result in more rotating mass, this is not always the case. It depends on the wheels and the tires. Some larger aftermarket alloys are lighter than smaller steel wheels. And tires vary widely in their weights.

Even if the larger wheel/tire combo is heavier, are you more interested in off-the-line acceleration or handling in corners? You might be willing to give up a little initial acceleration in order to take the corners faster.

Post by **matthew1** » 21 Apr 2009, 10:19

I actually like the look of the steel wheels. I had a '78 Porsche 924 with the base steel wheels, and I painted the centers black/left the rim silver (worked at a paint store in high school, drove the car right in the back of the store and did it one Sunday when there were no customers in -- or maybe there were

). It looked great. Maybe I'm nostalgic.

I'd by lying if I said I haven't been thinking about looking for some cheap steel 15s with tires since I saw tjts1's post.

Leev, I answered your question in another thread so we can leave this one on-topic. Gotta practice what I preach.