10-12-2014, 12:18 PM | #1 |
Lieutenant Colonel
217
Rep 1,909
Posts |
Lightweight Rims/Tires for E70 ?
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 ? Last edited by 007_e350; 10-12-2014 at 12:45 PM.. |
10-12-2014, 03:41 PM | #2 |
Captain
107
Rep 994
Posts |
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
|
Appreciate
0
|
10-13-2014, 07:03 AM | #3 | |
Lieutenant Colonel
217
Rep 1,909
Posts |
Quote:
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 |
|
Appreciate
0
|
10-13-2014, 12:38 PM | #4 |
Captain
107
Rep 994
Posts |
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... |
Appreciate
0
|
10-13-2014, 01:15 PM | #5 |
Lieutenant Colonel
217
Rep 1,909
Posts |
F the looks I'm not gonna do it - actually replace RFTs with regulars and save couple lbs
Last edited by 007_e350; 10-13-2014 at 02:06 PM.. |
Appreciate
0
|
10-13-2014, 08:27 PM | #6 |
Captain
70
Rep 600
Posts |
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.
__________________
PAX5
BMWCCA 20645 |
Appreciate
0
|
10-14-2014, 02:57 PM | #7 |
Major
1023
Rep 1,168
Posts |
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.
|
Appreciate
0
|
10-14-2014, 04:30 PM | #8 |
Lieutenant Colonel
1190
Rep 1,544
Posts
Drives: '22 Tesla MY + '23 Tesla MY
Join Date: Jul 2010
Location: Land of high taxes and crappy healthcare
|
I'm running lightweight forged wheels by Rennen and they were relatively inexpensive compared to the people paying 8-10k for adv.1
__________________
| '22 Tesla Model Y P - My daily | '23 Tesla Model Y LR - Wife's daily | '17 F15 35D - missed daily |
|
Appreciate
0
|
Post Reply |
Bookmarks |
|
|