E36 Rim & Tyre problem

[BMTech]

Hi AllI have a problem and was wondering if you are able to shed some light.I just got an 1992 (UK spec) E36 318iThe orginal stock tyres for my car was 185/65-15" based on specs I got from tirerackBased on tyre claculator,All other options on a 15" Rim will work out to be faster or slower. The closest I got was:1% fast - 195/60-15" or0.9% slow - 205/60-15"On the 16" Rim 215/50-16" will obtain 0% difference.My tyre now is 215/55-16" and it is scrapping the inner wall of my car when I make a full U turnWould changing to215/50-16" solve this problem and would using 195/60-15" also solve this problemAppreciate any advise I can get as I am rather confused on what to do to solve this problemThanks

 

[SarJeePekAi]

By calcumathing yr wheel+tyre height u can almost tell the problem>>

a. 215/55 16 = 64.29cm
b. 215/50 16 = 62.14
c. 195/60 15 = 61.5

so go figure.....

 

[BMTech]

Hi Sarjee,

Thanks for the maths..... based on those figures which should be the right size for the E36?

sorry still very new to this game

 

[anaksarawak]

Normal standard size are

15" rims - 205 60 15
16" rims - 215 50 16
17" rims - 215 45 17

Other forumers may help.

 

[bmw7833]

BMTech, how u calculate this:-

1% fast - 195/60-15" or
0.9% slow - 205/60-15"

...???

 

[BMTech]

Hi 7833,

got the calculations from the Tyre calculation site below

http://www.miata.net/garage/tirecalcold.html

 

[Lee36328]

185 65% 15 19.7 Stock
215 55% 16 20.7 0.9 more (or less) than stock 215 50% 16 20.2 0.5
195 60% 15 19.6 -0.1

 

[SarJeePekAi]

By calcumathing yr wheel+tyre height u can almost tell the problem>>

a. 215/55 16 = 64.29cm
b. 215/50 16 = 62.14
c. 195/60 15 = 61.5

so go figure.....

d. 205/60 15 = 62.7cm [std size]

As set d. is the optimum height then i guess dat anything
over the ht of 63cm will cause inner well scrubbing.
solution would be to use b. and c. hope it workzzzz.....

 

[BMTech]

Thanks Guys,

I can now conclude that

the Stock Tyres 185/65-15" - Dia 24.5" (62.23cm) should be optimum as designed by BMW, thus

using 215/50-16" - Dia 24.5" (62.23cm) gives the same diameter and revolution ( no change in Speedo meter reading) should be the best for a 16" Rim

I wonder though how this will fare in terms of comfort, fuel consupmtion and power as compared to stock 185/65-15"

 

[anaksarawak]

Some E36 is with 215 60 15

 

[syahruln]

The tyre scratched the wall due to its height or width?

 

[BMTech]

Hi Syahruln

Both Height and width as the rubbing marks on the inside wall are on the inner front as well as inner side (Back)