Tyre Pressures?

[DeanB]

Surely the manufacturer's quoted pressures are always the "cold" pressures?

Maybe, but maybe not since the critical pressure is the 'operating ' pressure and to achieve the correct pressure when the tyre is warm you would need to start from a different place on a cold day compared to a hot day for example, or if you were driving gently on the road compared to hard on track.

All of this is pure speculation of course - perhaps we should ask Lotus or look at a handbook (who reads the instructions anyway?!?).

[Simon Mac]

One thing I don't get about tyre pressures is with all the Lotus technical experience and relationship with the tyre manufacturers why they recommend 26F 29R. They must publish these figures for a reason????

Mark

 

I would hazard a guess as to get the best CO2 figures.

 

/cynic

[Meister]

Maybe, but maybe not since the critical pressure is the 'operating ' pressure and to achieve the correct pressure when the tyre is warm you would need to start from a different place on a cold day compared to a hot day for example, or if you were driving gently on the road compared to hard on track.

All of this is pure speculation of course - perhaps we should ask Lotus or look at a handbook (who reads the instructions anyway?!?).

Hi Dean

Tyre pressures in the manual are definitely cold tyre pressures and then it clearly states the problem of under/over inflation of the tyres. Now don't get me wrong on track I run 22F 24R and it feels right as I adjust back down to those pressures every few runs. BUT....ever since I got my first Lotus I posted up ( Here and Seloc ) and was told 22 - 24F 24-26 R and I followed that advice, but next track outing I am going to try the book figures and I will report back! Those higher psi figures quoted must be for a reason? (Simon - I'm not totally convinced it's for the emissions).

You could argue that it it reduces tyre wear at those higher psi figures but on Seloc they suggest it increases wear in the centre of the tyre??

Mark

[un1eash]

Increase wear in the centre of the tyre is a clear sign of over inflation.

[Meister]

Increase wear in the centre of the tyre is a clear sign of over inflation.

Which makes it even more interesting that Lotus didn't spot that themselves when testing.

[cjwjames]

Hi Dean

Tyre pressures in the manual are definitely cold tyre pressures and then it clearly states the problem of under/over inflation of the tyres. Now don't get me wrong on track I run 22F 24R and it feels right as I adjust back down to those pressures every few runs. BUT....ever since I got my first Lotus I posted up ( Here and Seloc ) and was told 22 - 24F 24-26 R and I followed that advice, but next track outing I am going to try the book figures and I will report back! Those higher psi figures quoted must be for a reason? (Simon - I'm not totally convinced it's for the emissions).

You could argue that it it reduces tyre wear at those higher psi figures but on Seloc they suggest it increases wear in the centre of the tyre??

Mark

I'm confused . Com ..so very interested on your feedback Mark

Hi Dean

Tyre pressures in the manual are definitely cold tyre pressures and then it clearly states the problem of under/over inflation of the tyres. Now don't get me wrong on track I run 22F 24R and it feels right as I adjust back down to those pressures every few runs. BUT....ever since I got my first Lotus I posted up ( Here and Seloc ) and was told 22 - 24F 24-26 R and I followed that advice, but next track outing I am going to try the book figures and I will report back! Those higher psi figures quoted must be for a reason? (Simon - I'm not totally convinced it's for the emissions).

You could argue that it it reduces tyre wear at those higher psi figures but on Seloc they suggest it increases wear in the centre of the tyre??

Mark

I'm confused . Com ..so very interested on your feedback Mark

[Steve J]

F 21 R 24 cold

 

On track I adjust as on clockwise tracks front left tends to get hotter / higher pressure. 

[stockhome]

22/24 on my zzr's.

 

I think anything around those figures will be ok... Good old tyre fitters.

Scatty i have read that ZZr's have a much higher operating pressure 30PSI according to the avon website

 

http://www.avonmotorsport.com/road-legal/performance/zzr

[scatty]

Scatty i have read that ZZr's have a much higher operating pressure 30PSI according to the avon website

 

http://www.avonmotorsport.com/road-legal/performance/zzr

Thanks for that Sheldon, I shall check them next time she's out. Looks like I'm a bit flat....

[Alex B]

Thanks for that Sheldon, I shall check them next time she's out. Looks like I'm a bit FAT....

EDITED FOR ACCURACY

[cjwjames]

EDITED FOR ACCURACY

Pmsl .. ohh dear

[AlexD]

EDITED FOR ACCURACY

nice one Alex

[Martin R]

I would presume Lotus quote figures for the tyres that the cars left the factory with. How many people still use those? Also they are probably figures for road driving and NOT on track.

 

I guess to work properly the tyre needs to be the same temp across all the surface? If you are really that bothered get an infrared tyre thermometer and check it after use. Adjust the pressure till its the same across all the tyre surface.

[Alex B]

I'm still on RE040

[Martin R]

I'm still on RE040

 

I wonder for how long?