My maxima is slower with my aftermarket wheels and tires.. Why?

[DevonD]

Hey. I have a 96 Maxima Se and since the snow is melting away i threw my summer tires and rims on it. 0-60 i dont think has changed but once im on the highway it is so much slower! i used to be able to get it up to 235 km/h on a level road and now it wont even touch 200 going downhill. The overall height of the tire is only about a centimeter taller than stock and im confident there is less weight. so why is it suddenly so much slower? Thanks!

[Trav1s]

What was on the car over the winter?

What size are your summer wheels and tires?

Generally, larger size wheels are heavier. Additional rotational mass impacts performance. I think I read somewhere 10 lbs of rotational mass is equal to 100 lbs added to the car.

If the summer wheels/tires weigh 10/lbs per wheel more than the winter wheels then it is like adding 400 lbs of weight to the car. (This is illustrated in the 00/01 Maxima numbers with 15" steelies, 16" alum and 17" aluminum wheels)

[DevonD]

wow ya i could see that impacting the performance alot. But over the winter i just had the stock 15" rims with just some pretty standard winter tires. The rims on it now are 17" aluminum wheels with a low profile tire on it. Like i said before the tire height difference is only about a centimeter, if even that much! I just sort of assumed they woud be lighter becasue the stock were pretty chunky rims and the ones now are a five spoke pattern and there looks to be alot less metal on them.

[Trav1s]

Never underestimate the weight of the wheel. I quickly earned this lesson on my old Sentra GXE (1.8/auto). Picked up 16" Sentra SE/SE-R wheels because I hated the look of the stock steelies and hubcaps. I bet the 16" combo weighed 15-20 lbs per tire/wheels more than the stock 14" steelies/tires. Acceleration suffered but handling was better.

[the converted]

You also have to remember that the really heavy part of the rim is an inch futrher out than it was before and that has a huge impact on the amount of energy it takes to spin them.

[dr-rjp]

Hey. I have a 96 Maxima Se and since the snow is melting away i threw my summer tires and rims on it. 0-60 i dont think has changed but once im on the highway it is so much slower! i used to be able to get it up to 235 km/h on a level road and now it wont even touch 200 going downhill. The overall height of the tire is only about a centimeter taller than stock and im confident there is less weight. so why is it suddenly so much slower? Thanks!

More than likely your aftermarket wheels are at least 17"in diameter, and even if the combination of tire and wheel is the same as it was with your stock wheels (which probably were 16"), they probably do weigh more.

Regardless of weight, a 15" or 16" rim will give you better, low-end acceleration but less top-speed than a 17" or 18." The change in rim size causes a change in the final drive-ratio

[DevonD]

Alright, what your all saying makes perfect sense but im not sure i understand how the final drive could change when the overall tire height is the same size? weather its a 10" rim with a 8" tire or a 17" rim with a 1" tire isnt the outside circumference still going to be the same so not changing the final drive? im not arguing im just curious..

[nj1sh]

yea this explains why my mpg is poor.

[the converted]

im not sure i understand how the final drive could change when the overall tire height is the same size?

Don't worry, it doesn't.

[Trav1s]

Regardless of weight, a 15" or 16" rim will give you better, low-end acceleration but less top-speed than a 17" or 18." The change in rim size causes a change in the final drive-ratio

1. If the overall tire diameter is 1 mm different then the change in the final drive in minimal. Less rotational mass improves acceleration and top speed. As I said before, rotational mass is more of a killer than people realize.

2. How does the size of the wheel/rim impact final drive? I am sorry but this confuses me...