tmux

I let someone borrow my car and I didn't notice until weeks later that he had overinflated my tires to ~55psi on 2 of the tires, 30's and 40's on the other 2. Chalk it up to a bad gauge at whichever gas station and him not knowing about the built-in sensors visible in the dashboard.

I guess the numbers weren't a big deal because I drove a few weeks without problems and the dashboard didn't issue any warnings. But it got me wondering, what are long term effects of having overinflated tires?

This is more of a general question but mods seem to like to route all my threads here anyway lol. I guess the specific model can make some difference.

BROlando

Ride quality issues and wearing the centre of the tyre out first are both overinflation related issues.

You sure the pressures were what you measured? That would (should) have set off a light in the dash...

tmux

It was actually the dashboard display showing 55psi, I never tried a separate analog gauge.

t3hhcaptain

I actually run my fronts at about 46psi and the rears at 35ish. I don't think the light will come on for being over-inflated, but like BROlando said, those are the issues.

Most tires I've seen aren't supposed to go over 54psi or they can blow out.

Just reduce the pressure and it'll be fine.

tmux

What is the advantage of this? Bouncier?

BROlando

I think the sensor also reads 55psi when it has failed (but don't take my word on that).

You should check with a decent gauge to be sure.

BROlando

My guess is gas mileage and/or handling balance.

t3hhcaptain

Bolstering sidewalls and better contact with the road. I autocross frequently and just leave them at my desired specs.

Good info here if you are curious: https://www.tirerack.com/tires/tiret....jsp?techid=58

thoiboi

So, great for 'competition' handling, but for daily driving, probably unnecessary, you'd say?

t3hhcaptain

Eh, I don't know. Unnecessary? Sure. Still handles better on the road. I suppose it's more subjective and preference based than anything.

Give it a try and see how you like it.

WheelMcCoy

Good comments all around, but I need some clarification. I take it the *front* tires were at 55 psi and the *rear* tires were in the 30's and 40's? Or were the pressures all mixed up among the 4 tires? Also, did you measure the tires cold?

Agreed. While higher pressures in the front stiffen the sidewalls and can reduce oversteer in FWD vehicles, the smaller contact patch will increase braking distances.

tmux

The link says to return to normal psi when back on street lol.

t3hhcaptain

Give it a try if you want, don't if you don't, lol.

I'm gonna keep doing what I do.

tmux

Yes, front were both ~55, 1 rear was 40's, other rear ~35.
I only noticed when cycling through my dashboard info, never measured with a gauge. Was cold.

tmux

Oh yea it's interesting stuff. I tried it inadvertently for a few weeks due to not noticing the pressures. I guess I drive too tame to have noticed a difference . Hands are tied being in a more urban environment recently.

RTM

Maybe your friend was autocrossing your car?

I've personally found most cars handling goes down when tires are overinflated, but I don't autocross.

tmux

Haha, probably not as he was visiting and used it to visit relatives.
Can you elaborate on the handling differences? Like response lag to your steering wheel turns?

t3hhcaptain

When you increase tire pressure you are making the tread push out. Both over-inflation and under-inflation will worsen handling.

You'll notice on the sidewall of your tire some dots below where the tread stops. These are all the way around. You want the tread to contact just at the top of these dots. The pressure I run accomplishes that. It's a front-end heavy car which is why I run so much in the front. It'll vary depending on tires too.

Edit: Could just be weather fluctuation that made them so high: https://www.tirerack.com/tires/tiret....jsp?techid=73

https://www.tirerack.com/tires/tiret...e.jsp?techid=1

RTM

Don't feel like I have a good grip on the road, doesn't handle in turns as well, ride gets really bouncy. Nothing specific like "at 40mph into the hard left turn on the Hwy 92 uphill it slides out"

WheelMcCoy

Just wanted to point out that Acura and tire manufacturers specify the psi not just for handling reasons. They factor in tire wear and road noise as well. It's a balancing act. Over-inflate or under-inflate by 10% and I'd say you're still within balance (engineers always build in a margin of safety). +10% will accommodate hyper-milers and canyon carvers. -10% are for softer rides. Beyond those boundaries, however, you need to know what you are doing, i.e.: track driving and auto-crossing (hard) or driving on a beach (soft).