Tire Size Question...Please Help

[PettitWC]

Hello everyone. I have 17 x 8" rims and they now have 225/40/17 Kuhmos on them. I will have to replace two of them and I wanted to go with 235/40 for out back. I found some real cheap ones on e-bay the other day (like $115 for 2 tires shipped) but I missed out on the auction so now I'm thinking of other ideas.
Any ways, I was wondering if anyone was running different sidewall sizes f/r (w/a different width i suppose it would almost even out though) or if anyone had any suggestions on what I should do...ie: would it be better to keep 225's all around or would i really benefit from 235's?
fyi: my car is lowered like 1.5" or so
thanks in advance for advice :biggrin:

[L84THSKY]

Well, if you use different size tires front and rear, you can't rotate them. That's the first problem. I'm running Dunlop Sport 8000 tires 235/45/17 now for my summer wheels. No rubbing feels great.

Hello everyone. I have 17 x 8" rims and they now have 225/40/17 Kuhmos on them. I will have to replace two of them and I wanted to go with 235/40 for out back. I found some real cheap ones on e-bay the other day (like $115 for 2 tires shipped) but I missed out on the auction so now I'm thinking of other ideas.
Any ways, I was wondering if anyone was running different sidewall sizes f/r (w/a different width i suppose it would almost even out though) or if anyone had any suggestions on what I should do...ie: would it be better to keep 225's all around or would i really benefit from 235's?
fyi: my car is lowered like 1.5" or so
thanks in advance for advice :biggrin:

[aceyx]

Kumhos are usually very competitively priced. I'd try and find a set locally, that way you're getting free mounting / balancing (~$20) and not paying shipping (usually ~$7 / tire).


I know that doesn't quite answer your question, but that's my input.

[PettitWC]

thanks guys. I think I will end up going with 225's but the only problem is they're tough to find with a 40 aspect ratio, especially locally. I was thinking about finding some used ones so they would maybe wear out around the same time as the front ones and then i could just go 235/45 all around...

[L84THSKY]

I paid $270.00 for (4) used Dunlop Sport 80000's 235/45/17 on Ebay. They had 90% of the tread left.

thanks guys. I think I will end up going with 225's but the only problem is they're tough to find with a 40 aspect ratio, especially locally. I was thinking about finding some used ones so they would maybe wear out around the same time as the front ones and then i could just go 235/45 all around...

[PettitWC]

I paid $270.00 for (4) used Dunlop Sport 80000's 235/45/17 on Ebay. They had 90% of the tread left.


hahahaha, man you and e-bay, but that's where i've been looking so we'll see

[aceyx]

I hope you're not buying motorcycle tires that way too.

Auto is fine (you've got four), but I wouldn't risk an old production date on a bike.

[L84THSKY]

My motorcycle tires are new, however, I would buy NOS tires to get original "Made in England" Dunlops

I hope you're not buying motorcycle tires that way too.

Auto is fine (you've got four), but I wouldn't risk an old production date on a bike.

[H3_2.1-ti]

Guys who's been advising you on tire sizes? I'm sorry to have to tell you but you are both runnig the wrong size for your cars. We sell tons of tires at the shop for BMWs and have never seen those sizes on E36s. Here are the sizes that fit an E36 318ti on all four corners:

185/65/15, 205/60/15, 205/55/16, 225/50/16, 215/45/17, 225/45/17, 235/40/17, 225/40/18, 235/35/19

The outside diameter of the tire must always remain within 2% of the o.e. size to avoid gearing problems. The 225/40/17 size is border-line depending on the wheel width, but the 235/35/17 size is definitely the wrong size for an E36 at 3.5% bigger in overall diameter. It is a size for an E34, E39 5 series.

I would recommend a 235/40/17 for a wider tread that will put more rubber down, protect the wheels and avoid gearing issues.
Cheers,

[L84THSKY]

My 235/45/17 tires only offset speed by 2.6% higher than normal.


Guys who's been advising you on tire sizes? I'm sorry to have to tell you but you are both runnig the wrong size for your cars. We sell tons of tires at the shop for BMWs and have never seen those sizes on E36s. Here are the sizes that fit an E36 318ti on all four corners:
185/65/15, 205/60/15, 205/55/16, 225/50/16, 215/45/17, 225/45/17, 235/40/17, 225/40/18, 235/35/19
The outside diameter of the tire must always remain within 2% of the o.e. size to avoid gearing problems. The 225/40/17 size is border-line depending on the wheel width, but the 235/35/17 size is definitely the wrong size for an E36 at 3.5% bigger in overall diameter. It is a size for an E34, E39 5 series.
I would recommend a 235/40/17 for a wider tread that will put more rubber down, protect the wheels and avoid gearing issues.
Cheers,

[Sekurit]

I'm running 225/45 up front with 245/40's in the rear. Those are sitting on 7.5F/8.5R OEM M3 Contour's. But my compact is not yet lowered though.

[Viper3812]

I have Z3 Cross Spokes (BBS) with 225/45/17 up front and 245/40/17 in the rear with a 1.25" drop and have Dunlop FM901's, cost me $85 a tire.

[1rstbmw!]

Im running 225/45/16 just had them put on today would that cause any gearing problems?

[cali-ti]

you can calculate the diameter difference (and thus effect on your speedo) using this: http://www.miata.net/garage/tirecalc.html