Does high tire pressure cause more pothole/suspension damage

The potential damage to the vehicle is going to vary greatly, depending on whether the tire pressure is slightly higher or a lot higher. Calculating if it's worth it is beyond my ability. Higher tire pressure isn't worth it to me, but a lot of people here would disagree.

 

depends also if your hauling major butt. The tires' sidewalls will need to absorb the shock with excess weight pushing down like 3 others passengers with junk in the trunk so thats when you need to PSI on up. 99% of the time I drive by myself and know the common roads driven on well so I can be on all 4s at 44PSI with no major road bumps or marijuana holes.

 

It seems to me higher pressures have to stress bearings and suspension more. Tire has less give; the shock will be transmitted more. I raise pressures, but only 2~3 pounds above spec.

Also, I go over all speed bumps at a dead-crawl. And try to avoid malls where there's a lot of them. Find it a little absurd when they're placed every 20 feet or so, someone's lost touch with reality.

With speedbump infested malls too: you'll see a lot of drivers doing dangerous manuevers, driving up the parking stalls, on the wrong side of lane, and so on.

 

Why isn't anybody just satisfied with getting 50+ MPG?!?

It's kind of funny, we all buy a car that gets fantastic gas mileage right from day one, but then many guys do all kinds of weird experiments to try and increase that mileage even more. 50 psi? Bone jarring! The people with the gas-guzzling Dodge Chargers and Mustangs and Ford trucks... they should be the ones jacking up the tire pressure. Not Prius owners.

I've been adjusting tire pressure, trying various levels for 2.5 years. But not because I wanted better mpg. I've been trying to reduce the darn tire noise. And with all that, I never noticed any big improvement in mpg. (But I did notice a lot more suspension noise at higher psi. That's not good.)

 

Clearly we need to borrow Hummer's central tire pressure management system (inflate/deflate all 4 from the dashboard even while underway) and couple it with a GPS receiver and a road condition database.

It airs down on bad bumpy roads, it airs up on smooth ones. Transparent to the driver.

 

I have always hyper inflated my tires, I use less fuel and replace tires less often.

Given I have always done this, and the fact that I don’t seem to ever replace a rim, a spring, a control arm, a strut over hundreds of thousands of miles I am uncertain what costs there really are.

That said I am usually very mindful of the road and avoid potholes and keep my speed down.

The potholes that could break something are likely so severe that tire inflation would not be the deciding factor

Ah well

 

I average 47-48mpg. 80% is highway. I'm very happy! I was getting 22mpg from my Town & Country.
36psi.

 

I have a problem with the term "suspension damage". I've never see that on any vehicle I've owned unless something very bad was hit, such as a very deep pothole or a very large object was run over. In that case, higher pressure will -probably- help protect the wheel, but the tyre may be damaged, even though it looks fine. I have always used 40 PSI front and 38 PSI rear. I go up to 42 PSI front and 40 PSI rear in the winter due to the cold lowering the tyre pressure. All pressures measured at "room temperature" (STP).

Oh, and Mendel, I do slow down a bit for speed bumps but not very much. I don't think they would cause any problems, based on the fact they haven't so far, and it's been a lot of years.

 

I use to keep 42 psi on my previous Gen3 Prius, but ever since I got Prime, I have been keeping it mostly at ~37 psi. I tried a few pouns higher on Prime, but did not see much change on MPG, but it got too noisy and uncomfortable with the OEM Dunlop tires. At 37 psi, I am getting 66 MPG (HV only), so I am happy with that.

 

I did snap a rear spring on my '04. Ran psi in the mid 40's. It happened when I loaned it to someone else. When it came back I saw the left rear was hanging low. She hadn't noticed and said she didn't hit a pothole or anything.

 

My (fairly new) Michelin Premier tires are only 5 or 6 psi over the recommended specs (on the door sticker.) But who do you believe for psi... Toyota? Michelin? I'm currently at 42/41, any higher than that and I start hearing the hatchback creaking & groaning and some suspension noise. But I would like to get as much tread life as possible, without damaging suspension components.

(I can't complain about the gas mileage. I drive briskly, in the Normal mode with the AC on every day. I don't know why, but I always got worse mileage when I put it in the ECO mode. And I hate that "mushy" gas pedal feel.)

 

YES. The tire flex is figured into the suspension design.
A couple of extra pounds, OK, more than that is a risk.

 

So the 60psil I ran 240000 miles in my Insight must have been fine, since suspension and everything else was original

 

60 psi ???

Educate us. Seriously.

Did they ride like rocks?
How did the tread look?
Any uneven wear?
How was the handling in the rain?
How was the stopping distance in both wet/dry?
We're the tires any noisier?
Any suspension noise?
How much did the mpg improve?
And what brand of tires?
How long did they last?

Thanks.

Oh, and did you need any dental work after those 240K miles?

 

Coming from a 1981 Comutacar the Insight was a regular Cadillac

 

Maybe the Gen4 Prius suspension is more sensitive or something, because I can feel & hear every tiny bump, small crack, little rock, twig, stone, leaf, bottle cap, banana peel, raisins, M&M's...

The OEM Toyo's were loud, and the Michelin Premier tires are no quieter. I give up. They should give you free earplugs with those tires.

 

Yes and specifically the special Insight size which is made of unicorn farts and rainbows,
That tire on a Gen 1 Prius or even my Chevy Cobalt seems to add +10% to fuel economy ,
It is a specially made “fuel economy performance “ tire that is otherwise terrible in every other way.

 

That's a joke, right ?

Just because you "got away with it" does not make it OK.
There may have been suspension wear that you were not aware of.

AND......I don't know of any tire of the proper size for an Insight that is engineered for pressures that high.
Anyone who actually does that should be more worried about catastrophic tire failure and not the suspension.

 

You tell 'em, Sam! I don't think I believe his fish story.