ipp

Do I have to say more?

BetterMakeWay

Yes ipp you can say more. If you indeed point out the rim size regarding the discussion. I brought up a topic on this in lounge. You see Formula 1 cars are way different than our street cars. And their main difference (regarding ur topic) is in suspension. Our cars have very different structurated suspension, "vertical suspension"and that acts differently from what F1 uses. Closer to F1 suspension is the Carrera GT (among other cars) which has the shocks and springs mounted rather horizontally.

For that matter if you give the motorsport as the example than take a look at more familiar sports and closer to our cars like: WTCC or Fia GT. Look there what tires/rim sizes they run.

BetterMakeWay

Agree ATS but our cars and ferraris none the less come with the widest posible tires on those rims. If you want to imrpove what you say, then you've got to run wider tires on wider wheels. And again, once with the increase in width comes generally and increase in height also.

Straight line acceleration won't be affected if the diameters are virtually (almost the same; only a few mm difference) and also the weights is pretty close also.

For example: I wanted to go with wider tires with my STOCK 18" style 135M rims. But 245 tires are the maximum for 8" width (of the 135M rims). So if i wanted to go for wider tires i had to search for other rims, wider ones. Now there are few rims that are on 18" and on 8,5 or 9" width. Most of them are on 19" diameter. Considering this i also wanted a look factor so the increase to 19" was not enough, having 18"s also. I decided to go 20"s with wider tires both front and back. Now for sure the new combo will be heavier than my stock one, but that's mainly because of my limited budget. Straight line acceleration will be decreased by some margin but due to the big torque i found that on 18"s with RFT i had to struggle to find the grip not too loose too much time by spinning in excess. By putting wider tires/rims this will help the grip, even more considering this summer remap which will put an extra stress of 100NM on the rear wheels. So it may be a balance here by the time lost from the extra weight vs the time gained by the extra traction.

So considering this a Ferrari owner will for sure afford a super light 3 piece rim (not lilke me) made of magnesium alloy with titanium bolts etc etc so that the outcome would be pretty much the same but with a big plus in the LOOK (of course if it's done tastefully and rationally).

ipp

You are probably right... But it would be very interesting to see a scientistic test with the same car (eg. a 5er M-Sport) running the same track with different wheels.

BetterMakeWay

I would also be very interested in that.

ALTANertive

The bigger the wheels the worse performance all around. Acceleration, handling, braking. Unless the wheel is significantly lighter than the smaller wheel it replaces. Even if a 20" wheel is lighter than a 19" wheel. The performance will generally be negative as you're pushing the weight out further. 19 is considered borderline bling already. Anything 20 or over is bling. If you have a wide tire but no side wall your acceleration will be worse as you're losing sidewall flex necessary for launches and such.

BetterMakeWay. You say F1 cars are different than street cars. I completely agree. But look at DTM. They run 18's. I'm sure if they were allowed to in the regulations most teams would be running smaller wheels. And then you compare with RFT tires that are notorious for being horrible performers so much that BMW does not put them on M models, and instead opts for the mobility kit. It was not an apples to apples comparison as the tire type was different. Maybe a change in air pressure was all that was necessary.

There is a video somewhere on youtube of a stock M5 vs an M5 with the 21" Hartge wheels. The stock M5 eventually pulls away.

pinguhk

1 sexy car

pinguhk

big wheel only look good and they perform badly.
that why my S2000 have the 16 instend of 18" better handling

BetterMakeWay

Oh come on...soon on this judgment would be better to see Lambos, Zondas and Keonigssegs with 16" cuz 19" is already borderline bling. You have a point though about the launch and how it impacts the sidewall flex, although i'm not convinced it is a good point. So it seems it's better overall to roll on 16" with 55 tire sidewall? Cuz if we take to extreme we can see that dragsters have such big tire sidewall.

I really doubt that if it were regulations free they would run smaller than 18".
Abstract from DTM regulations: The front axle has 9x18 inch wheels and the wheels on the rear axle measure 11x18 inches
You try and find in after market for the E60 and in fact even for a E90 rims with 11" width but on 18" height.

I'm so sure a GT3 RS would perform better on a 17" 50 tire profile.

ALTANertive

You're first paragraph has me confused as first it seems you disagree w/ me but then bring up dragsters to support it.

I think the obstacle here is you keep referring to wheels that race cars/teams are using, then trying to find the same layout in a mass-produced consumer form. That's not going to happen because the entusiast/weekend racer accounts for only a small percentage of sales. That's why there are wheel manufacturers that offer custom applications. Obvisouly they cost a lot more so are not available to your average consumer.

You got larger wheels that were heavier, so you compromised performance for styling. There is nothing wrong with that, but it just feels like you trying to justify or convince yourself that the added weight has no negative impacts. Again it's not a complete apples to apples comparison as your tire size AND type are different. Given the same wheel size, tire size, and compound, the lighter wheel wins, period.