Tyre sizes

[4eyes2wheels 0]

Toying with the idea of new wheels and perhaps keeping the old ones for winter wheels and putting winter tyres on them. Having been caught out on tyres sizes before :bad-words: I was wondering what size choice there is. For example I'm on 15 inch Speedlines with 205/50/15 tyres. Tyres in this size are £80 ish where as in 195/50/15 some makes are only £40. Sure there is some allowance for budget Asian makes versus premium makes but what's the deal with tyre sizes.

 

I know this is a bit of a numpty question . . . .

[mattnorgrove 0]

You really need 205/50/15 to keep the rolling radius the same, 195/50/15 will give a smaller radius, knocking out your speedo/odometer.

 

Kuhmo KU31 can be found for around £50 a corner, and come very highly recommended, brilliant performance for such a budget tyre....

 

HTH

[Alex_G60_Fanatic 0]

Toying with the idea of new wheels and perhaps keeping the old ones for winter wheels and putting winter tyres on them. Having been caught out on tyres sizes before :bad-words: I was wondering what size choice there is. For example I'm on 15 inch Speedlines with 205/50/15 tyres. Tyres in this size are £80 ish where as in 195/50/15 some makes are only £40. Sure there is some allowance for budget Asian makes versus premium makes but what's the deal with tyre sizes.

 

I know this is a bit of a numpty question . . . .

 

hey hey!

 

They use a stupid system with both metric and imperial measurements! Its very confusing so i'm not surprised your having trouble

 

basically you need to get a tyre that gives you the same overall Diameter, Like matt said. There is a handy calculator here that helps. The way hey do it is like this For your tyre the:

 

205 = the width of the tyre in mm

50 = the percentage of the width that makes up the rim (eg. the bit between the alloy and the road surface that forms the tyre wall) in your case 50% of 205

15 = the diameter of the alloy wheel

 

if you want a different tyre you'll have to get a different set of alloys

[4eyes2wheels 0]

Thanks chaps!

[dukest 0]

If you want to use 195s you don't need different wheels, the speedo won't be significantly out.. Valvers used 195s anyway as they were lighter/slower.

The only questions are whether you still feel happy with a slightly narrower contact patch and whether, if you bin it, you feel confident the insurance company won't pull you up for non-standard tyres.

[4eyes2wheels 0]

Perhaps the easiest thing to do is stick to one set of wheels and tyres . . . .

[Alex_G60_Fanatic 0]

If you want to use 195s you don't need different wheels, the speedo won't be significantly out.. Valvers used 195s anyway as they were lighter/slower.

The only questions are whether you still feel happy with a slightly narrower contact patch and whether, if you bin it, you feel confident the insurance company won't pull you up for non-standard tyres.

 

it wont alter the speedo much its true...

 

If you car was set up to run on 205/50 on 15" then if you go down to 195's then you'll be going at 71.69mph when your speedo says 70mph... so no great crime! However you will be putting on the miles quicker onto the clocks. The choice is yours

and if Dukest is right then you may be running your car on the wrong tires anyway... maybe THATS the question you should be asking... What was the original tyre size on the car... :shrug:

[mikkijayne 0]

Kuhmo KU31 can be found for around £50 a corner, and come very highly recommended, brilliant performance for such a budget tyre....

 

I'll second this. I'm running KU31s on 17s on my valver and they rock 8) They are easily a match for my previous favourite tyre - the Eagle F1, and for £50 a corner they are outstanding value. I wouldn't be disappointed if I'd paid double that for them in terms of performance.

 

Its looking like they'll last about 13K on the front, so not quite up there with the premium tyres, but I do drive it quite hard. I've always found you get what you pay for when it comes to tire life, so these are about right.

 

Oh, and regarding tyre sizes, the speedo in mine is spot on with the GPS now I have 205 40 17, so I don't think 205 or 195 50 15 is really going to matter :wink: