How About 20" wheels on a 3.0?

[mspillberg2000]

Hi X5 FANS;
I had a question....I got a 2002 3.0 X5... ( No sports pkg)
I have 17inch factory rims and I just upgrade my wheels to 20.
It seems like that I am not getting the same power that I used to...
Do you guys know anything that can help me get my horsepower back? Will this hurt my engine? It seems like I am towing something!
How bad this will effect my gas millage?
It looks great, I just don't want to hurt my engine...

Thanks for your feedback very much

[JCL]

Do the new wheels have the same rolling diameter? If not, what you have done is change the gearing.

If they are the same effective size, any impact is likely from the inertia of the wheel. More weight at the rim means more resistance to changes in rotational velocity, when you accelerate or brake.

Only you can determine the impact on your mileage. Test it and see. I would expect the change you made to reduce the throttle responsiveness (it may feel a little slower off the line), reduce mileage, and reduce ride quality. On the other hand, it will turn in better in the corners.

Can't see how it will hurt your engine, but there are trade-offs to larger wheels, and you are likely seeing them.

Perhaps someone who has done the same swap can comment.

[mspillberg2000]

Thanks for you guys feedbacks...I got the exact 20 sizes that 4.6 has ..Front is 275/40/20 and the rear is 315/35/20... It used to be 215/50/17 I think...(FACTORY WHEELS) I have Toyo Proxies on them and I love the look and the ride is much more comfortable...It feels more like the sedan than an SUV...
It seems like somehow I need to get more power in there... I am not sure how much my gas millage will get effected!
I am just afraid my engine may go bad since the wheels are heavier.. ANy suggestions?
How about perfomance chips? Will it help?

Thanks again

[wc18]

Yes, you will "feel" less power. The larger wheel will cause you to take longer to accelerate to the same speed then before because the 20" wheel/tire combo are heavier (more rotational mass) than the 17" wheel/tire combo. Drag racers say adding 1 lb of rotational mass "feels" like adding 5lb to the weight to the car.

- wei

[Krunk Man]

if you want to see some serious power loss on a 3.0 add some 22x10.5 rims and see your mpg go down to 13.9

[hayaku]

Originally Posted by wc18

Yes, you will "feel" less power. The larger wheel will cause you to take longer to accelerate to the same speed then before because the 20" wheel/tire combo are heavier (more rotational mass) than the 17" wheel/tire combo. Drag racers say adding 1 lb of rotational mass "feels" like adding 5lb to the weight to the car.

- wei

to add, 10lbs of weight loss = 1hp regained in unsprung weight (which wheels and tires are). your heavier rims and even heavier tires have added quite a bit of unsprung weight.

[dkl]

Originally Posted by hayaku

to add, 10lbs of weight loss = 1hp regained in unsprung weight (which wheels and tires are). your heavier rims and even heavier tires have added quite a bit of unsprung weight.

FYI...I did a rough weighing on the wheels and tires a while back. The difference between the OEM 17" and the OEM 19" are roughly 10 to 12 pounds each (60lb vs 70lb front/72lb rear). So...just going from 17" to 19" will add about 44lb of unsprung weight. I could only imagine that the 20" will weight an additional 5lb or so more on each wheel...and possible more if you go with the replicas.

BTW, I am seeing about 14mpg city and 22mpg highway on the 19s.

[janagler]

I just put on a set of replica 4.6's on my 2002 3.0 last week and I absolutely love it. I have the Toyo Proxies which are awesome tire and the grip have certainly improved. The decrease in speed off the line is minimal and the ride quality is about the same, maybe a tiny bit worse with the 20's, but then again I live in Boston and the roads are awful here. If you like the look and can afford to do it, I think it is an awesome upgrade. Good luck.