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#1 Tyre Pressures
Posted: Tue Mar 17, 2015 5:35 pm
by vee eight
Hello to all,
What would the forum suggest is the correct tyre pressures front and back for 185-15 radial tyres on a 4.2 series 1 roadster.
Thanks
#2
Posted: Tue Mar 17, 2015 5:40 pm
by Heuer
32psi all round is a good place to start although my personal preference is 30 at the front and 35psi at the rear.
#3
Posted: Tue Mar 17, 2015 9:38 pm
by Nick
David,
They do say that the IRS is sensitive to tyre pressure, but what difference do you feel +3psi makes ?
And 30 at the front rather than 32 ? For ride or roadholding ?
Nick
#4 Re: Tyre Pressures
Posted: Tue Mar 17, 2015 11:08 pm
by PeterCrespin
vee eight wrote:Hello to all,
What would the forum suggest is the correct tyre pressures front and back for 185-15 radial tyres on a 4.2 series 1 roadster.
Thanks
'Correct' for what?
When Graham Hill tested an E they put 50 psi in because thry knew he liked his tyres hard. After a few laps he came in and asked for more. Not the same tyre of course but you'll just have to see what suits YOU best with your tyre brand, roads and driving style. The only thing it costs is a bit of your time.
#5
Posted: Tue Mar 17, 2015 11:19 pm
by Heuer
What Pete says. It has taken me years of testing to find what suits my driving style. A matter of finding a test route and running it over and over again with small incremental changes until you get what you want. Bear in mind temperature and load affect what you feel. As I said start with 32psi and test from there.
#6
Posted: Wed Mar 18, 2015 11:10 am
by Heuer
Here is what Jaguar had to say on the subject:

So yes, a small change in tyre pressure can alter the characteristics of the car and Jaguar did a lot of testing to prove it. Note the warning
".... it is most important the following tyre pressure recommendations are followed"
Check your tyre pressures regularly!
#7
Posted: Wed Mar 18, 2015 7:29 pm
by vee eight
I wanted a base figure to start at, so that question has been answered
i.e. 32 lbs-sq in. Thanks
#8
Posted: Wed May 20, 2015 12:49 pm
by dougal
Hi
I think it is worth noting that the Dunlop Tyres mentioned were the SP41. which is different to the SP Sport that is currently available. I think this current SP Sport came out in 1968. does anyone know better?
I would still suggest fitting the Pirelli Cinturato or Michelin XVS. They are actually made by Pirelli and Michelin.
This is a new film that we have just made showing you the tyres.
#9
Posted: Thu May 21, 2015 11:22 pm
by timhum
I'm trying to learn and understand what difference a change in tyre pressures will make to handling/roadholding. If we use the example of 32psi all round and drive the car then change to 30 front 35 rear what difference should I be able to detect? Is it correct that an increase in pressures results in greater adhesion and a lower pressure less? Sorry if I seem a bit dim but just trying to get my head around the subject.
Tim
#10
Posted: Thu May 21, 2015 11:29 pm
by abowie
timhum wrote: Is it correct that an increase in pressures results in greater adhesion and a lower pressure less?
Tim
Other way around. High speed results in more rotational torque and greater lateral forces in turning. High pressure makes the tyre harder to deform.
Try letting your front tyres down to 20psi and take it for a drive. Very heavy steering because there's more tyre in contact with the road. Then pump them up to 40psi and do the same drive. Light steering.
#11
Posted: Sat Jun 13, 2015 8:52 am
by TrevS
Sorry to revive this post but I am looking for what tyre pressures to run on my series 1. The car is running Pirelli P4000 Super Touring 205/70 ZR 15 95. Any help would be much appreciated
#12
Posted: Sat Jun 13, 2015 1:00 pm
by Moeregaard
As David mentioned earlier in the thread, 32 PSI all around is a good starting point. With 185-15 Avons on my E-Type, this pressure just worked well for long-distance touring. Since you're running non-standard tires, you'll need to do some experimenting.
#13 Re:
Posted: Fri Nov 11, 2022 8:47 am
by dougal
TrevS wrote: ↑Sat Jun 13, 2015 8:52 am
Sorry to revive this post but I am looking for what tyre pressures to run on my series 1. The car is running Pirelli P4000 Super Touring 205/70 ZR 15 95. Any help would be much appreciated
Eek!
Take them off and throw them away.
Sorry to be the barer of bad tidings. But these are really old.
https://www.longstonetyres.co.uk/pirell ... p4000.html
I checked these out with Pirelli. At best they were made in 2011.
To be frank they aren’t very good for an e-type any way specially a 6 cylinder car.
They were good tyres. I had them on a series 3 XJ12 when I bought it.
However think how much happier you will be when you treat yourself to a set of proper 185-15 tyres. It will be so much nicer to drive. Get the hood stuff Cinturato or XVS. You won’t regret it.
#14 Re: Tyre Pressures
Posted: Fri Nov 11, 2022 1:58 pm
by caveman
I went from Avon to Cinturato earlier this year……big difference, costly but reassuring when pushing the car.
