Overinflating tyres

[MakaveliX]

Tyres are 195/50r 16V

I used to run 35 at the front and 32 at the back ( as per Toyotas advice ) , but recently tried 35 all round. Seems to roll better but obviously more bumpy, is this normal ?

What PSI do you guys run your tyres ?

So even if you are a driving enthusiast like me, is it always best to run them at what the manufacturer say ? I was under the impression that over inflating the rears by 3psi might make the car roll nicer and feel more sporty

[E-bmw]

I have played around with tyre pressure before on cars to improve ride/handling, I am currently in a V50 which says 32/32 lightly laden, but it felt really crashy at that.

After a bit of fiddling, I have settled on 30/29 & the car drives significantly better.

[thebraketester]

Honestly I am amazed you can feel 3psi difference in tyres on the road.

[Aunty Pasty]

I usually go to 42 psi as opposed to 41 on the sticker. Mainly to allow for a little leakage when I disconnect the pump.

If you over-inflate, you'll get lower rolling resistance, lower grip and a harder cashier ride. The degree to how this is affected I can't say but I doubt 3 psi would make much difference.

[MakaveliX]

Aunty Pasty said:

I usually go to 42 psi as opposed to 41 on the sticker. Mainly to allow for a little leakage when I disconnect the pump.

If you over-inflate, you'll get lower rolling resistance, lower grip and a harder cashier ride. The degree to how this is affected I can't say but I doubt 3 psi would make much difference.

Thanks everyone.

That's why I use an analogue tyre pressure guage. More accurate than a pump, and you can let out tiny bits of air until you get to the desired PSI. I'd assume you already are aware of this

[wong]

Aunty Pasty said:

I usually go to 42 psi as opposed to 41 on the sticker. Mainly to allow for a little leakage when I disconnect the pump.

If you over-inflate, you'll get lower rolling resistance, lower grip and a harder cashier ride. The degree to how this is affected I can't say but I doubt 3 psi would make much difference.

Long term, you also may get more tyre wear in the middle of the tread and less on the sides.

[Zarco]

Lower pressure at the back is to promote rear grip on a FWD car. Same pressures all round and it might be a bit more tail happy.

[E-bmw]

MakaveliX said:

Aunty Pasty said:

I usually go to 42 psi as opposed to 41 on the sticker. Mainly to allow for a little leakage when I disconnect the pump.

If you over-inflate, you'll get lower rolling resistance, lower grip and a harder cashier ride. The degree to how this is affected I can't say but I doubt 3 psi would make much difference.

Thanks everyone.

That's why I use an analogue tyre pressure guage. More accurate than a pump, and you can let out tiny bits of air until you get to the desired PSI. I'd assume you already are aware of this

Sorry, that is a gross assumption & will likely be more wrong than right.

Analogue gauges are very sensitive to knocks, vibration, poor storage, even changing the orientation of the gauge can change the reading.

Digital gauges are far more stable & will retain accuracy (assuming accuracy to start with) over a wide range of situations even including serious abuse.

You go on to say analogue is better than a pump. A pump is an air delivery device, not a pressure measuring device, so that is also wrong.

[Dave Brand]

Manufacturers don't always get it right!

Citroën recommends 2.4 bar front & rear for the DS3, Michelin recommends 2.2 for the front. Dropping the fronts to 2.2 firmed up the steering to a noticable degree & also evened up wear - the tyres were wearing slightly more in the centre.

[wong]

Manufacturers also suggest overinflating rear tyres when carrying heavy loads (5 seats all occupied?)

[Panamax]

wong said:

Manufacturers also suggest overinflating rear tyres when carrying heavy loads (5 seats all occupied?)

That's not overinflating - that's correctly inflating.

[wong]

Panamax said:

wong said:

Manufacturers also suggest overinflating rear tyres when carrying heavy loads (5 seats all occupied?)

That's not overinflating - that's correctly inflating.

Yeah, I stand corrected.

[wyson]

thebraketester said:

Honestly I am amazed you can feel 3psi difference in tyres on the road.

I found it depends on the car. I found Honda’s with double wishbone suspension, you could really feel the difference. On a car with McPherson struts up front and multilink rears, not so much.

[Pica-Pica]

wyson said:

thebraketester said:

Honestly I am amazed you can feel 3psi difference in tyres on the road.

I found it depends on the car. I found Honda’s with double wishbone suspension, you could really feel the difference. On a car with McPherson struts up front and multilink rears, not so much.

With many cars that would be the difference between a single driver and a full load. So yes it would be noticeable by some drivers. My car tyre label recommends front/rear pressures of 35/38 and 38/41 for a full load. That is a staggered set-up. My preference for driver-only is 37/40.

[PaulKemp]

You should measure tyre temp across the width both edges and the middle in several places around the tyre if you want to muck about with manufacturers recommendations.
If you overinflated you get a high spot in the middle, under inflate and the edges are high and the middle low, temp after a strong run can also show if geometry is off

[Tony1963]

PaulKemp said:

You should measure tyre temp across the width both edges and the middle in several places around the tyre if you want to muck about with manufacturers recommendations.
If you overinflated you get a high spot in the middle, under inflate and the edges are high and the middle low, temp after a strong run can also show if geometry is off

Yep. I’ve recommended this for years, but people seem to prefer complicating their lives. I would add that it’s best to go for a steady drive without and hard cornering or braking to achieve a more representative set of readings.