Tamora tyres
Author
Discussion

Madmatt V8

Original Poster:

478 posts

221 months

Monday 12th April 2010
quotequote all
Hi all :-) does anyone know if I can put 255/35/18 tyres strait on the back wheels of my tamora for more grip? Many thanks tiivers :-)

Madmatt V8

Original Poster:

478 posts

221 months

Monday 12th April 2010
quotequote all
I was told by someone in the tyre trade that the 35 profile is related to the width so a 35 on 255s will be about the same as a 40 on 235s
is this a fib from him ? Lol

shep1001

4,620 posts

218 months

Monday 12th April 2010
quotequote all
Madmatt V8 said:
Hi all :-) does anyone know if I can put 255/35/18 tyres strait on the back wheels of my tamora for more grip? Many thanks tiivers :-)
Width wise I believe they are OK but the rear should be 40 profile not 35 otherwise this will impact on the speedo readings.

Shep

madbadger

11,752 posts

273 months

Monday 12th April 2010
quotequote all
shep1001 said:
Madmatt V8 said:
Hi all :-) does anyone know if I can put 255/35/18 tyres strait on the back wheels of my tamora for more grip? Many thanks tiivers :-)
Width wise I believe they are OK but the rear should be 40 profile not 35 otherwise this will impact on the speedo readings.

Shep
Neither 255 profile gives quite the same outer circumference.

I have 265/35 on the rears which works out as the same as the original 245/40.

I wouldn't worry too much about the speedo. It is so accurate to start with you will not be far off. Quick check with a GPS will tell you how accurate it is.

The tyre width you can go to depends on the wheel width. Spiders are 8", SP12s are 8.5" so can take a slightly wider tyre.

madbadger

11,752 posts

273 months

Monday 12th April 2010
quotequote all
Madmatt V8 said:
I was told by someone in the tyre trade that the 35 profile is related to the width so a 35 on 255s will be about the same as a 40 on 235s
is this a fib from him ? Lol
It is not really about the same.

The first number is a %age of the width, so 255/35 are 89.25mm of rubber. 255/40 are 102mm.

Original 245/40s are 98mm, so 255/40 are closer than 255/35



Edited by madbadger on Monday 12th April 10:38

Madmatt V8

Original Poster:

478 posts

221 months

Monday 12th April 2010
quotequote all
Ah I see, my originals are 235/40 on the back and 235/35 on the front. I hope that's right. Should I go for 245/40 on the back instead of 255/35 ? Just need a bit more grip as it spins a bit lol I know I could drive slower before anyone comments lol :-)

madbadger

11,752 posts

273 months

Monday 12th April 2010
quotequote all
That's interesting! Mine were 245/40 Rears and 225/35 Fronts. Probably whatever was in the factory at the time.

Do you have the standard spiders? The wheel width is the important thing really. From memory 245s are about as wide as you should go on the 8" wheels.

The circumference needs to be about the same to avoid speedo error which on 18" wheels is determined by the height of the tyres.

out of interest.

  • 235/40/18: d in mm = 457.2 + 94 + 94 = 645.2 x pi = 2027mm
  • 245/40/18: = 457.2 + 98 + 98 = 653.2 x pi = 2052mm
  • 255/40/18: = 457.2 + 102 + 102 = 661.2 x pi = 2077mm
  • 245/35/18: = 457.2 + 85.75 + 85.75 = 628.7 x pi = 1975mm
  • 255/35/18: = 457.2 + 89.25 + 89.25 = 635.7 x pi = 1997mm
  • 265/35/18: = 457.2 + 92.75 + 92.75 = 642.7 x pi + 2019mm
So the biggest potential difference is for each rev of the wheels there is 102mm difference in how far you travel.



Madmatt V8

Original Poster:

478 posts

221 months

Monday 12th April 2010
quotequote all
That is interesting lol yes they are the standard 18 spiders. So it looks like the 245/40s are the best safe option then.
Thank you all for your help and comments :-)

Targarama

14,784 posts

312 months

Monday 12th April 2010
quotequote all
Madmatt V8 said:
Ah I see, my originals are 235/40 on the back and 235/35 on the front. I hope that's right. Should I go for 245/40 on the back instead of 255/35 ? Just need a bit more grip as it spins a bit lol I know I could drive slower before anyone comments lol :-)
There is no need to drive slower. You can drive more quickly by learning how to apply the power more evenly and thus not brreaking traction (cheaper on tyres too).

Laser Sag

2,860 posts

272 months

Monday 12th April 2010
quotequote all
I think you will find that the spiders are 8.5 inches wide and will take up to a 265 tyre, and from experience you can use 255s on 8 inch wide wheels without a problem

T66ORA

3,474 posts

286 months

Monday 12th April 2010
quotequote all
I have used 255/35x18 on the back of my Tamora for the last 4 years, no problem with clearance/scrubbing, no problem with the Speedo, and they lower the gearing slightly, so in theory, should make it slightly quicker through the gears.You will get slightly better grip, in the dry. Going to 35 profile i was expecting the ride to suffer slightly, but in the end i couldn`t tell any difference.
When i need to replace the rear tyres again i will be buying 255/35s again.

Madmatt V8

Original Poster:

478 posts

221 months

Tuesday 13th April 2010
quotequote all
Thank you again for your comments and help. Do you have a picture of the 255/35s in the car? Be nice to see what they look like.

Many thanks :-)

T66ORA

3,474 posts

286 months

Tuesday 13th April 2010
quotequote all
Not a lot to see, but any excuse to post a pic of my car biggrin

Barry Ashcroft

1,958 posts

250 months

Tuesday 13th April 2010
quotequote all
I also have the 255/35/18's on the rear and have had no problems

Madmatt V8

Original Poster:

478 posts

221 months

Tuesday 13th April 2010
quotequote all
Sweet very nice mate. Will be getting a set of those then :-)

Barry Ashcroft

1,958 posts

250 months

Tuesday 13th April 2010
quotequote all
Here you go 255 Goodyear F1 Assymetric



And a nice arty one


madbadger

11,752 posts

273 months

Thursday 15th April 2010
quotequote all
Some interesting information in this article: http://www.pistonheads.com/gassing/topic.asp?h=0&a...

I think the title may be misleading due to the increase in weight with the bigger wheels but there does seem to be some good increases in grip and braking on wider tyres.

SeiW500

255 posts

197 months

Thursday 15th April 2010
quotequote all
Tart!

Barry Ashcroft said:
And a nice arty one

Barry Ashcroft

1,958 posts

250 months

Thursday 15th April 2010
quotequote all
SeiW500 said:
Tart!

Barry Ashcroft said:
And a nice arty one

You missed a good trip mate