enti98

Im planning on putting a new set of 19's avantgarde SL63 reps on my C350, and Id like to know if wheels like that would decrease performance in terms of acceleration, turns, etc.?

This will be my first mod btw which is why im asking

ShaiMalka

DOO IT! post pics as soon as there on I'd love to see them on

QuadBenz

If the wheels you're going to be putting on are heavier than the rims that are currently on your car, then yes you'll notice decreased performance.

whiteongrey

The Madhatter at bimmerforums.com sums it up perfectly.


"Less weight at the end of each axle will always be quicker then more weight. think of it as free horsepower for your car.

running heavier weight wheel/tire combos will:

kill your fuel economy
kill your acceleration
kill your handling - your suspension has to work harder
kill your suspension - it'll wear out faster
kill your braking distance
kill your brake hardware - wears it out quicker
kill your wallet - more expensive


the average weight of an 18" wheel is around 26lbs for a descent wheel. many replica or cheapo wheels weigh in at 28-35lbs per wheel.

I've switched from 18's back to 17's and noticed a dramatic improvement in my car's dynamics.

the same thoughts above apply to big brake kits (BBK). Getting a massive brake rotor for a bbk (some weigh as much as 35lbs per rotor!) is going to kill your car's dynamics"

Distalero

Add to this general information the fact that it effectively changes the final gearing, from just a bit to a more significant amount, so in effect it's like opening your transmission and changing out gears to the same amount, all assuming that the new combination of tire and wheel is not exactly like the factory set up. Net result: slower acceleration off the line (this is a better explanation than "kills our acceleration") because it's a higher gear.

Thing is, no plus combination is exactly like the factory set up unless you are very lucky, and no plus size combination is necessarily like another for that matter, so there is a slop factor involved in any change.

But, if you're into image, or a "statement", then none of this will influence you, and unless you've really gone to the extreme, you won't really feel it "seat of the pants" either.

kevink2

Effect on Acceleration

1) assume the tire OD of the new 19" combo does not change from oems.

It's likely weight per corner will increase. Assume 10 lbs increase per corner, 3600 lb curb weight, 160 lb driver. That 10 lbs/corn will increase dead weight of car by 40 lbs. The effective added weight due to more wheel/tire rotary inertia is a theoretical max of another 10 lbs per corner, but more likely about 8 lbs/corner for a +1 upgrade case.

So, total rolling weight with driver has increased by 72 lbs, from 3750 to 3822, a 2% increase. This will result in 2% slower acceleration and braking ... not much.

2) assume new 19" set has 26" OD tires, vs 25" oem.

The gearing effect noted before will decrease acceleration 4%. And if 10 lbs/corner heavier, the rotary inertial effect on "rolling weight" could be much more than the 10 lb limit in case 1 .

Handling and Comfort

Again assume 10 lb per corner increase. Assume oem unsrung weight ( brake tire wheel etc ) per corner is about 70 lbs. A 10 lb increase is a 14% change ... much more significant. This will make the suspension's response to bumps more sluggish, for a rougher ride, and less able to keep cornering grip on rough roads.