Which tyre size?

OXO · Dec 13, 2013

I have some 7J 16" wheels for M+S winter tyres for the p38.

What size tyres should I go for?

thinking of 225 75 R16 which is +0.81% on circumference

or 215 75 R61 which is -1.225 circ

wammers · Dec 13, 2013

P38 should be on 8J rims. But if you fit 255 you would need 255/65/16 and if you fit 215 they should be 215/75/16. The 255s will give you the correct rolling radius the 215s will give you 59.3 MPH at 60 indicated. Why would you fit narrower tyres and wheel rims for winter? Does not make a lot of sense to me.

discomark10 · Dec 13, 2013

thin is better for snowy roads, deep snow wider is better

OXO · Dec 13, 2013

Well mainly because I have some disco rims.. actually, I think it would be better because the load per area on the contact patch will be greater with the narrow rims, so better to push through snow and slush. Of course I may be wrong..

This has caused me to wonder if the car has the correct tyres on it now. They are (standard wheels) 255/55/18.

That comes out at 2318mm circumferencer, and your suggested 215/70/16 is 2221, so I think I already have the wrong ones.

wammers · Dec 13, 2013

discomark10 said:
thin is better for snowy roads, deep snow wider is better

Well you should know, specially with the blizzard conditions you get in Milton Keynes. Maybe he should fit some push bike tyres then. Although my experience would say somewhat different to your theory.

Thor1950 · Dec 13, 2013

discomark10 said:
thin is better for snowy roads, deep snow wider is better

Ya like on a snow cat

wammers · Dec 13, 2013

OXO said:
Well mainly because I have some disco rims.. actually, I think it would be better because the load per area on the contact patch will be greater with the narrow rims, so better to push through snow and slush. Of course I may be wrong..

This has caused me to wonder if the car has the correct tyres on it now. They are (standard wheels) 255/55/18.

That comes out at 2318mm circumferencer, and your suggested 215/70/16 is 2221, so I think I already have the wrong ones.

Sorry my mistake see the previous post i have amended it. 255/55/18 are standard size. Put 255/60/16 in to calculator should have been standard 255/65/16. Buggered the end result up.

Here do it yourself. http://www.kouki.co.uk/utilities/visual-tyre-size-calculator

OXO · Dec 13, 2013

What do you think about width on 7J rims? Is 225 too wide?

wammers · Dec 13, 2013

OXO said:
What do you think about width on 7J rims? Is 225 too wide?

According to the rules it is but it's up to you. If you look down the link i posted there is a guide to rim and tyre size. According to that 255s are too wide for 8J rims. But Land rover fit them as standard.

Which tyre size?

OXO

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wammers

No longer with us, RIP

discomark10

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OXO

Well-Known Member

wammers

No longer with us, RIP

Thor1950

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wammers

No longer with us, RIP

OXO

Well-Known Member

wammers

No longer with us, RIP

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