Catfood

Porsche put 15" rims on most of there 944s. Lots of people like to buy aftermarket rims and such, many times 16" or so. Ive even seen big old dubs on a 44.

So my question is what kind of advantages do rim size give you? what are the advantages to having bigger rims. Handling, acceleration? Do they degrade the performance?

If Porsche put 15s on them I'm sure thats the optimal size for a well rounded car, but if I put wider ones one will my handling go up? even if acceleration goes down.

ibkevin

Don't be ascardt to use the "search" function, many people do and it saves them this embara....

This has been covered extensively.

theiceman

To maintain the same overall wheel diameter bigger wheels mean shorter tire sidewall. Shorter tire sidewalls are moe ridgid and resond much quicker to steering input and enhance handling remarkably., Side walls also have less flex and make for less " body roll" under high speed maneuvering.
Smaller wheels wich provide larger sidewalls enhance comfort at the expense of some handling. The larger sidewall flex allows it to ride over bumps and absorb some of the shock. Also helps if you hit a large pothoe. MAY not destroy your rim.
Porsche tries to pick the best compromise of handling and comfort.

billthe3

Larger wheel = larger tire, larger brakes, more brake cooling, stiffer sidewalls (because of lower size) producing a stiffer ride, looks

smaller wheel = less rotational weight, larger sidewalls for a softer ride, cheaper

Keithr726

iceman hit it right on target. Now rims width is another story, but generally the bigger the better.

billthe3

Not for the price of tires.

Keithr726

true, forgot that one.

Catfood

what about acceleration? how much speed do I lose by going from 15" to 16", I could care less about a smooth ride.

Keithr726

You won't loose any speed, acceleration should be better but you won't be able to tell.

shiners780

Depends on the wheels.

My 17" Forgeline wheels w/ Toyo RA1 tires, compared to the stock 16" phonedials with the same tires, are the exact same overall diameter, lighter, have stiffer sidewalls, all while being wider. In this case, much to gain/nothing to lose.

Cost of tires is all part of the grin-factor. That's like thinking about what kind of gas mileage you're getting. Who cares?

gtroth

--seems like there are more tire choices these days for > 15" rims.

Mighty Shilling

Lord knows I haven't

Legoland951

By going from 15" to 16" 225/50 for both sizes, I lost a lot of time on the track. Bigger does not mean better from the track point of view. I have seen someone go from 17 dot R tires to 18 full race (not the dot R compound tires) and actually lost time. There is also easier tire spin from a larger diameter wheel since there is not as much sidewall to absorb the launch or acceleration. Look at most race cars (F1, Indy, NHRA, etc) and you won't see tiny sidewalls with respect to wheel diameter for whatever the reason. Bigger diameter wheels are mostly for looks in my opinion.

Darwantae951

True, but doesn't Porsche use 18s on all their factory Cup cars? I'd have to think that there is some advantage to 18s over 17s, 16s, etc... I was reading an article about a Carrera 2.7 RS in excellence and they specifically noted that you could feel the flex in the body from the tires and it made them somewhat reluctant to push it in the corners (that and it was a $130,000 car). Maybe people just weren't used to the new behavior of the new wheels/tires and made mistakes?

-Darwin

JayP

The reason F1 and NASCAR mandates small wheels is to keep cornering speeds low(ish) and limits brake sizes.