View Full Version : what size tires on my car? .. specs inside...

Justin e36
08-18-2004, 06:11 PM
I'm driving a e36 .. 318i. (lighter engine)
I'll be lowered on M3 struts/shocks and Eibach Pro springs. (approx 1.5" front and 1.0" rear drop.)

My rims are:
FRONT: 18 x 7.5
REAR: 18 x 8.5

I'd really love to put 255's on the rear.. but it'll be way too heavy for my poor little 4-banger engine.

What rubber sizes should I go with?

I'm thinking maybe 225/40 18 Z front and 235/40 18 Z rear?

I notice some people put 225/[b]35[/n] 18 Z for the rear... any reason for this? ... should I go with 40 all around or 35's in the rear? why?

also would I have a problem with 245's all around? ... I can get a good price on Potenza's...

08-18-2004, 06:46 PM
the 35s would be smaller diameter, so it would help your gearing a bit (better accelaration). However, this might be a really small difference. You should find out what the stock tires are, then compare various sizes to get as close to stock as possible. Here is a good link for tire sizes:

08-18-2004, 07:28 PM
Your stock size is 205/60/15, correct? These are good matches, and I even included their comparative percentage. Anything below 3% is considered acceptable, and you wouldn't notice it.

225/40/18 +1.6%
225/35/18 -2.0%
235/35/18 -0.8%
245/35/18 +0.3%
255/35/18 +1.4%
...and it goes wider, but they wouldn't fit in the fender.

Your main concern right now is the wheel offset. I'm not a pro on E36 sedan fenders, but I'm sure Nelson or someone else will tell you what can and can't work with your wheel width and offset. If you plan on driving aggressively, especially on the track, go for 245's all around (IF it will fit). More neutral, better handling.

So basically don't buy tires until you post your offset.

Justin e36
08-18-2004, 11:13 PM
offset = +35

Justin e36
08-18-2004, 11:17 PM
btw scotch.. going to try to get those pics for you by end of the week... can't drive at the moment to the parts car to takke pics.

08-18-2004, 11:32 PM
Originally posted by Justin e36
btw scotch.. going to try to get those pics for you by end of the week... can't drive at the moment to the parts car to takke pics.

No prob ... make sure you get good shots of the damage, and any rust (inside trunk, strut towers, etc.)

Justin e36
08-19-2004, 01:50 PM
bump for tire specs..

Justin e36
08-19-2004, 02:05 PM
Originally posted by Mystikal
Your stock size is 205/60/15, correct?

Stock size for 92 318i was 185/65-15 according to tirerack.com ...

08-19-2004, 03:25 PM
I would go 225/40 (F) and 245/35 (R) for looks, overall protection for potholes and minimum speedometer error. You'll notice a big drop in performance with the heavier wheel/tire combo, so don't expect anymore "zippy" acceleration runs.

08-19-2004, 03:39 PM
FYI Stock size on a 318ti sport was 225-50R16. So don't be afraid that your engine will be overwhelmed (same engine), or that they won't fit your fenders (with stock offset.)


08-19-2004, 10:05 PM
Hey Justin I had to split my PM reply into 2 and the second one never made it, box is full. Lemme know when it's clear.

Justin e36
08-19-2004, 10:33 PM
Mystikal .. thanks for the info.. inbox clear...

08-20-2004, 01:14 AM
i've got 235/40/17 in front, 275/40/17 in back

08-20-2004, 02:19 AM
Originally posted by Justin e36
offset = +35 Justin, i'm running 225/40/18 on a 8"wide rim with a +35 offset and I rubbed in the rear with H&R Sports. If you're rolled then you should be good for 245/35 like Randy said.

08-20-2004, 01:01 PM
+40 is probably a better fit in the rear. I had 235/40/17s on 17x8 +40 rims, and even at the track (where the car rolls like a mofo) no rubbing at all.

Justin e36
08-20-2004, 09:17 PM
thanks for all the input everyone.

my problem with rolling fenders right now..... my passenger side recently started bubbling up with rust... and I'm not getting a bodyjob/paintjob till next summer.

So I'm going to go with...

225/40/18 - front
235/35/18 - rear

if I can find a 235/35/18 somewhere.

R_Jay.. .how much is the drop on H&R sports?