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Tyre Pressure for 205/40/17 ?

Posted: Tue Jan 09, 2007 4:10 pm
by ducktape69
what do you guys recommend for cold tyre pressure for 205/40/17 tyres?

keep in mind i want to keep even tyre wear but good performance....

Cheers,
Sam

Posted: Tue Jan 09, 2007 4:14 pm
by deez
When I had that size on my car I did 34-35 psi cold. The car felt quite good. Don't know if that helps :P

Posted: Tue Jan 09, 2007 4:33 pm
by lowmiata
I run between 38 and 40 cold
to protect the rims!
depends what type of roads you normally drive on!
QLD roads are not thye best!

Posted: Tue Jan 09, 2007 7:24 pm
by Boags
A lot... Don't know what that is in metric though! :lol:

Yep, over 35 cold for sure.

Posted: Tue Jan 09, 2007 7:32 pm
by Fatty
bloody hell. i only ever pump mine up to about 30 :?

mine are 16's

Re:

Posted: Tue Jan 09, 2007 7:44 pm
by Slugoid
Fatty wrote:bloody hell. i only ever pump mine up to about 30 :?

mine are 16's


30 seems a bit under inflated for me. I'm running around 34psi cold with 205/45R16's. I guess the best way is to play around and try different settings.

Posted: Tue Jan 09, 2007 8:03 pm
by Boags
Yep, I ran about 34PSI cold in the 16s on the track. Any less with the Fuldas and it felt too floaty. Dad used to run much higher than that for spirited road driving.

Boags

Posted: Tue Jan 09, 2007 8:22 pm
by timk
I use 32 cold on the SE rims, which seems good. When I first picked up the car they had 40 in them and that was way too harsh. For street tyres on track days I run 45 just while I am at the track to reduce sidewall flex.

Posted: Tue Jan 09, 2007 10:14 pm
by kev.yan
The pressures listed below will be a happy medium for most MX5's with most tyre sizes.
36- 38 psi Front
34- 36 psi Rear
If you drive Hard up the fronts another 2psi
also too Fatty if you by any slight chance have a warranty issue with your tyres, running below 32 psi invalidates any warranty on a modern steel belted tyre.
Hope this helps.
Kev 8)

Posted: Tue Jan 09, 2007 10:19 pm
by Fatty
guess i'll be ducking over to the servo tomorrow morning for a bit more air in my tyres then :oops: :oops:

Re:

Posted: Tue Jan 09, 2007 10:50 pm
by timk
kev.yan wrote:also too Fatty if you by any slight chance have a warranty issue with your tyres, running below 32 psi invalidates any warranty on a modern steel belted tyre.


That's really weird, the placard suggests 28 up front on the SE. Would it invalidate it in this circumstance?

Posted: Tue Jan 09, 2007 11:55 pm
by Boags
The race guys have said previously that MX5s run best with the same pressure all round. Just being a parrot.

Boags

Re:

Posted: Wed Jan 10, 2007 1:19 pm
by Charlie Brown
kev.yan wrote:The pressures listed below will be a happy medium for most MX5's with most tyre sizes.
36- 38 psi Front
34- 36 psi Rear
If you drive Hard up the fronts another 2psi
also too Fatty if you by any slight chance have a warranty issue with your tyres, running below 32 psi invalidates any warranty on a modern steel belted tyre.
Hope this helps.
Kev 8)


Crikey :roll: where did this info come from :?: Probably the English Cricketer’s dressing room during tactic discussions.

Mazda, you know the one who spent millions of $$$ developing the MX-5 and consulting with tyre manufactures, gives the recommended pressure at 28 or 29psi depending on the model. This gives the best ride, tyre wear and handling combination for the MX-5.
Now before everyone screams Mazda recommends those the pressures to suit a “comfortable” ride and not performance driving look again at what I’ve said.
If you want to move towards performance then increase the pressure, BUT only by about 2 psi. Keep in mind that when the pressure goes up, comfort and shock absorber life decreases and inner tyre wear increases.
For the track, raise the pressure to about 35 – 37psi cold. NEVER EVER let the pressure get above 41psi hot. Performance drops dramatically once this pressure is exceeded.

Also keep the front and rear pressures the same. The MX-5 has near enough to a 50/50 weight balance so front / rear pressure variation is not required for road use.

But back to your original query. As it’s 40 profile and not 45, put in 31psi and then fiddle up or down a pound or two to suit your requirements.

Posted: Wed Jan 10, 2007 3:16 pm
by mickfred
Hey here's a thought.....

How about using the recommended settings? :P

Posted: Wed Jan 10, 2007 4:53 pm
by ducktape69
thanks a lot charlie brown... always good to hear from experienced mx5ers....

i changed the PSI from 27 to 35psi COLD this morning.....ill probably drop it to 31 as it feels a bit harsh for normal driving.