01-16-2015, 08:28 AM | #1 |
Enlisted Member
19
Rep 43
Posts |
Highest height tire to be used on 18" wheel
I currently have factory 225/45/18 . The roads here overseas are terrible and I wanted to go with non runflat. Can i use a higher sized tire for a less harsh ride? Like 50?
|
01-16-2015, 09:11 AM | #2 |
Brigadier General
6803
Rep 3,166
Posts |
I purposely looked for a car with 17's. Modern cars don't have anywhere near enough tyre for snowy/icy climates and the resulting pot holes.
225/50 is a real nice profile, not too old school but enough tyre to get it done. I run that combo on both our X1 and 9-3. |
Appreciate
0
|
01-16-2015, 09:43 AM | #3 |
Enlisted Member
19
Rep 43
Posts |
Can I do that on my 18?
|
Appreciate
0
|
01-16-2015, 11:50 AM | #4 |
Enlisted Member
4
Rep 32
Posts |
I wouldn't use a 50 profile tyre on an 18" rim. It will slow acceleration and throw out the speedometer a bit too, making it appear you are travelling slower than you actually are. It may also affect other things like ABS.
I'd rather switch to a 17" rim to fit a 50 profle tyre |
Appreciate
0
|
01-16-2015, 11:51 AM | #5 |
Lieutenant Colonel
658
Rep 1,922
Posts
Drives: 2011 e91
Join Date: Jan 2013
Location: Calgary, AB, Canada
|
My summer tires have an overall height 1/2" taller than factory. Other than the speedo being out by 3 kms, it's fine.
__________________
2011 E91
2016 M2 - Sold 2014 X1 - Sold 2002 Land Rover Discovery II - 3" lift & 33s |
Appreciate
0
|
01-16-2015, 12:57 PM | #6 | |
Colonel
842
Rep 2,411
Posts |
Quote:
Acceleration is not noticeably affected at all by a couple % change, so I wouldn't sweet that. OP, are you still on runflats? Getting off of those god forsaken things goes a long way too. |
|
Appreciate
0
|
01-16-2015, 01:30 PM | #7 |
Enlisted Member
0
Rep 41
Posts |
If you're replacing run-flats with non run-flats, then the lower weight could help offset some of the inherent rotating mass gain from expanding the circumference. Run-flats do tend to weigh more at any given size.
Also, the speedometers seem be off anyway, and a greater circumference could actually help that. |
Appreciate
0
|
01-16-2015, 02:07 PM | #8 |
Major General
4457
Rep 9,160
Posts |
Yep, a bigger tire will actually correct the speedometer. I accomplished this by going wider with the same aspect ratio with my old car. No harm in going to a 50 series tire, as there is plenty of clearance on a stock X1.
|
Appreciate
0
|
01-16-2015, 02:38 PM | #9 |
Captain
60
Rep 675
Posts |
Speedometer and odometer can be corrected on our cars to match the real tire circumference and show actual speed. I did code different oem tires and now my speedo is off by 1 mph only with the original wheels and tires.
About the acceleration... Is it really be noticeable?! In theory yes but what about in real world? I'm also planning to put higher profile tires when my rfts are done. |
Appreciate
0
|
01-16-2015, 05:29 PM | #10 |
Freude am Fahren
108
Rep 278
Posts |
I'm about to buy tires in a couple of months and am having the same questions. Comparing 225/45/18 to 225/50/18 shows a 3.3% increase in circumference, therefore when the 45 series shows 60mph the 50 series will actually be going 62.1mph. I checked my X1 against a handheld GPS today, and the speedo was reading 60 when I was actually going 58 according to the GPS. So 50 series will actually correct it almost perfectly. That and the Michelin Pilot Sport A/S 3s are 30 bucks cheaper in 50 series I've about decided to go with the 50 series tire.
__________________
Current: 18 X3 xDrive30i Past: 03 530i Sport | 06 330ci ZHP | 14 X1 xDrive35i M-Sport | 11 328i M-Sport | 98 M Roadster |
Appreciate
0
|
01-16-2015, 07:01 PM | #11 |
Lieutenant Colonel
658
Rep 1,922
Posts
Drives: 2011 e91
Join Date: Jan 2013
Location: Calgary, AB, Canada
|
Your speedo will read correctly with a taller tire, but keep in mind that the odometer is separate from the speedo. It will measure incorrect mileage.
__________________
2011 E91
2016 M2 - Sold 2014 X1 - Sold 2002 Land Rover Discovery II - 3" lift & 33s |
Appreciate
0
|
01-16-2015, 09:25 PM | #12 |
Brigadier General
6803
Rep 3,166
Posts |
3.3% is riiiiight on the cusp of being just OK. Ideally one would come in below that.
TBH unless you're leasing i would sell the 18's and buy a set of 17's. Even in summer the car will ride better. I was running 225/45 on my Saab and it handles BETTER with the 50's because it doesn't scamper and hop over ridges in the road, there's more compliance. Mind you the X1 craps allover the 9-3 for handling. |
Appreciate
0
|
01-16-2015, 09:53 PM | #13 |
Lieutenant Colonel
658
Rep 1,922
Posts
Drives: 2011 e91
Join Date: Jan 2013
Location: Calgary, AB, Canada
|
If you want to put 44" tires on go for it, just as long as they all match in outer diameter.
__________________
2011 E91
2016 M2 - Sold 2014 X1 - Sold 2002 Land Rover Discovery II - 3" lift & 33s |
Appreciate
0
|
01-17-2015, 07:50 AM | #14 |
Private First Class
16
Rep 179
Posts |
If you go with a non-runflat the ride will be a lot softer.
My 20" rims wit non-runflat on them (I think 225/35/20 or 225/30/20, not sure but) is a lot softer the my stock 18" rims with runflats (size you mention 225/45/18 ). And I'm very happy with my Michelin Pilot Super Sports tires (on my summer set). :-) |
Appreciate
0
|
01-19-2015, 09:35 AM | #17 |
Private First Class
16
Rep 179
Posts |
The Wheel Fitment, Tyre Stretch, Rolling
Radius and Speedometer Error Calculator http://www.willtheyfit.com/ But I still don't understand why you go with other fitment then stock, just ditch the run flat crap and you got a much smoother ride. I ride on 20" (non run flat) and sport suspension. I has a smoother ride then 18" with run flat and stock suspension. (Of course now for winter I have my sport suspension and I need to ride with run flats on the 18" rims for the vehicle inspection.) Last edited by BeemerX1; 01-19-2015 at 09:41 AM.. |
Appreciate
0
|
01-20-2015, 02:06 PM | #18 |
New Member
0
Rep 5
Posts |
I recently ditched the run flats for the Michelin Pilot Sport A/S 3s. I wanted a taller and wider tire so I went with a 245/45 18. No issues whatsoever. If there is any decrease in acceleration its very marginal. Speedo is dead on now.
|
Appreciate
0
|
01-20-2015, 08:15 PM | #19 | |
Freude am Fahren
108
Rep 278
Posts |
Quote:
Just ran the numbers on your setup.....I like it!! Now let's see what Tire Rack has in this size.....
__________________
Current: 18 X3 xDrive30i Past: 03 530i Sport | 06 330ci ZHP | 14 X1 xDrive35i M-Sport | 11 328i M-Sport | 98 M Roadster |
|
Appreciate
0
|
01-21-2015, 11:53 AM | #20 |
Enlisted Member
2
Rep 31
Posts |
I tried the Michelin PS AS/3's in 245/45/18. While the tire fit no problem, I ended up swapping them for 225/45/18's. The 245's had unbelievable grip and were very plush but made the car wander all over the road. If you are going to the track, 245 might be a good choice, but for normal driving 225 is a good size for a square set up. Wow, what a difference these Michelin tires are from the run flats!
Last edited by Shredjim; 01-21-2015 at 11:36 PM.. |
Appreciate
0
|
01-21-2015, 01:48 PM | #21 |
New Member
0
Rep 5
Posts |
I know that the Michelin PS AS/3's come in two different speed ratings. The higher speed rated tire has a stiffer sidewall. This is the tire that I bought and I also have them inflated to about 42psi. I have had zero issues with them wandering on the road. They track very straight and handle excellent.
|
Appreciate
0
|
02-03-2015, 03:27 PM | #22 |
Enlisted Member
9
Rep 46
Posts |
I put 50's on my 18's for winter tires and it is fine, only thing is, if the wheel is turned to maximum. and you hit a rut or bump at low speed it rubs the liner a little bit. Very minor issue.
__________________
15 X1 35i Msport LeMans Blau/Schwarz |Ultimativepaket|JB4
07 X3 Monacoblau/Grau Prämie|KaltemWetter|Komfort|Navigation tschüss : ( 11 335d JBD Tiefseeblau/Oysterschwarz |Prämie|Navigation|KaltemWetter|Sportpaket |
Appreciate
0
|
Post Reply |
Bookmarks |
Thread Tools | Search this Thread |
|
|