large diameter wheels
 

Is there a real benefit to the driving and handling with say 20 inch tires for someone who is not a race car driver? All new cars today come with bigger and bigger tires and rims.
Every time I drive in a car with those big rims with low profile tires the ride is so hard my teeth rattle.
Am I missing something?


jz

I absolutely agree with you and think it's for "aesthetics" - not that they add any. I understand that the trend is going towards larger cars, but other factors should also be considered when design takes place. If you're interested about wheel fitment and spacing/offsets, take a look at the link below. Great, general knowledge to have.


Wheel Fitment & Spacing Guide

turbobandit uses big tires,not pussy tires has he calls them

No. Some time ago one of the auto magazines did a comparison on a car (I think BMW 3 series) between 15 and 19 inch wheels. They found going too large (18, 19") actually can hurt performance if the car is not tuned for those wheels.

Gas mileage suffers too. On a Jetta TDI (a more extreme example) I lost about 2-4% gas mileage going from 15" to 16" wheels and another 5% going from 16" to 17" wheels. So about 4 mpg going from 15" to 17" wheels, along with slower acceleration (it is noticeable).

Wide tires in front also affects steering. An old BMW 5 series feels better with 195 or 205 tires in front compared to 225, despite the fact the car grips better.

So I am not crazy thanks.
Back when I bought my 2015 ML 250 Bluetec it was listed as having 18" rims which I wanted , but they turned out to be 19's which the MB salesman termed "an upgrade". I bought the car and love it , but after the first 35K miles or so I bought fatter tires, going from 50 series to 55 series and the ride is noticeably "softer" over NJ's numerous potholes and bumps etc. But the MB dealer thought I committed a mortal sin. The tire diameter went from 29" to 29.5 ". I don't know what that does to the MPG but the ride is more forgiving and the pep seems unaffected.
Here's to fat....tires!
jz

Adding to Kenny's comment, these were the results. Basically, smaller wheel equals better MPG and acceleration at the cost of lower cornering g's and longer braking distance.

http://media.caranddriver.com/images...s-original.jpg


They primary reason to upsize, in my opinion, is to get access to higher performance summer tires. Going up to 16" will do that if higher performance is what you are after. In this test they used m+s tires on all sizes to keep it even but going with a summer tire will reduce braking distance considerably.

The reason modern cars have huge wheels is because the wheel arches and "belt lines" are much higher now. This is because of all kinds of safety requirements. The large wheels help keep the slabside look in check. It is also necessary to some degree to clear the huge brakes on modern 2.5 ton cars. Everything needs to stop like a Porsche now while weighing as much as a Cadillac.

Large diameter (or low profile) tires are popular because they help in cornering and because they look cool.

What is lost is the fact that wheel rims are heavier than rubber tires. So these assemblies have more rotational inertia, making them harder to accelerate and harder to stop. That's why gas mileage suffers. The assemblies also have more unsprung weight, which hurts comfort and reduces contact with the road when going over bumps.

Ive shoed the w123 models over the yrs with several variety of rims,i liked the 99c lk 16 in. rim the best.It looks retro ,fills the wheel well up ,then improves handeling as a topper .Ive never wore anything but the 205 55 16series tire,the next set I would like to try a wider taller tire ,215 60 16 perhaps.The largest diameter was a set of 19 brabus rims I found that need a little repair,Those where fantastic looking onmy blk 300cd ,the rear rims had cleared with no rub what so ever ,close though.The frts would need some help , I never rode these rims much ,you need a complete new frt end too establish control ,something this gripppey on the frt of an already heavy frt ended car makes for an old roller coaster road feel .They got sold shortly after fixing.The one fitment I would like to go back and explore is a 300sd with the nice correct yr look of a set of r129 rims, these fit but are a very close one,the look is stunning.