Lightweight Rims/Tires for E70 ?

[007_e350]

Folks, I have the 18" 209s with 255/55 all around on our diesel - I want to upgrade to sport widths (275/40/20 & 315/35/20- Dia is same) but weight seems to be the issue -

Total weight currently (w 18s) = 26.5 lbs wheels + 43 lb = 69.5 lbs
Weight w 20s (214 front) = 37.4 lbs + 32 lbs = 69.4 lbs
Weight w 20s (214 rear) = 42 lbs + 39 lbs = 81 lbs

Weights are from non-RFT tires on 20s - If you guys know of any other tire brand that weighs less pls let me know - I dont think this swap is worth the effort it'll definitely slow down the already sluggish diesel

ADVAN RDs have some 20s that weigh upto 25 lbs, but structural wise can we fit them on the X5 ?

[mitch808]

Anything forged will often be lightweight. But also expensive. Going to anything larger in rolling diameter, will make the car sluggish its more rotational mass to spin. You have to make a compromise if you want 20's or larger

[007_e350]

Originally Posted by mitch808

Anything forged will often be lightweight. But also expensive. Going to anything larger in rolling diameter, will make the car sluggish its more rotational mass to spin. You have to make a compromise if you want 20's or larger

Reading: Existing Wheel(209): New Wheel (Rear 214)

Diameter 737.7mm 728.5mm
Circumference 2317.6mm 2288.7mm
Poke 61.6mm 102.7mm
Inset 141.6mm 176.7mm
Speedo error 0% 1.26%
Reading at 30mph 30mph 30.38mph
Reading at 60mph 60mph 60.76mph
Ride height gain 0mm -4.6mm
Arch gap loss 0mm -4.6mm

[mitch808]

This has nothing to do with speedo error/overall tire diameter. take a 5lb weight in each hand, and spin around. Do that same thing, with the weights close to your body. Which is harder to do? i.e more effort...

Getting a larger wheel along with larger tire will mean your car will have to spin more mass at the wrong end. It looks better, but will add some extra effort required to spin.

Basically something has to give, and if you want a larger wheel, you have to live with the compromise. To counter that, you could go to a forged wheel, but at what cost? A 20" forged wheel that fits a BMW ain't cheap like something for a Japanese import in 5x100/5x114/5x120 in a popular size for Subaru/Mitsubishi/Honda/Etc... It's a shame that some of those wheels with tires cost more than 10-20% of the car...

[007_e350]

F the looks I'm not gonna do it - actually replace RFTs with regulars and save couple lbs

[PAX5]

Or do what I did:

Select a staggered 20" set from the previous e53 generation that you like. Bore out the hub to 74.1mm and fit your favorite tire (I choose Michelin Lattitude HP non RFT)...

I like the style 87 wheel (very difficult to find a nice set!). Other popular wheels are style 168. Both styles are NLA.
- 9.5x20 front, ET45, 12.46kg (27.4lbs)
- 10.5x20 rear, ET30, 14.33kg (31.5lbs)

The style 87 wheel will have a minimum weight savings of about 30% over most popular size 20" e70 wheels, all other things being equal.

[smyles]

TSW makes wheels for X5 under 'Beyern' brand that are "rotary forged" - no clue what exactly it entails beyond their marketing lingvo, but the set I have is super light, and with non-RFTs a 315 rear combo weighs less that a stock 18" RFT. While not the sexiest, given the price, IMHO it's an alternative to consider if you're concerned with weight.

[blue dragon]

I'm running lightweight forged wheels by Rennen and they were relatively inexpensive compared to the people paying 8-10k for adv.1