Tire pressure difference

[theholycow]

Yup, my experience is that cornering traction is always improved by increasing pressure, until it's high enough to cause a stiff bouncy ride.

[mikehallbackhoe]

an update on my subaru, it turns out I had a bad wheel bearing on the drivers side front, which might have caused my handling problem. now I don't know if the extra air pressure was the problem or not. I might try airing all four tires up and see what happens

[guest001]

I really need to bump up my pressure to max on my 88 740. I did it once, but that tanks data was fubar because I caught a nail in one of the tires some time right after.

[guest001]

Anyone have any comment on long term effects on tires inflating to max pressure? Ie. uneven or maybe accelerated wear?

[theholycow]

The only effect I've experienced is slight center wear. It is harmless...the center isn't bald yet when the other 90% of the tread width is down to the wear bars. More severe center wear would still be harmless in my opinion, water will still be channeled away by the non-center areas the same either way.

I've been doing this for a long time with a lot of miles on a lot of tires and that's been my experience.

[benfrogg]

Agreed, HC has it right.

My old tires had mild center wear, but the rest of the tread was beyond the wear bars. It was really not much different, just somewhat noticeable. I still say the added pressure is worth it for the overall fuel savings.

BTW, I have an 89' 740 turbo wagon with tire pressure at 50 psi. The only real issue us "squirly" handling, but that was there before the increase in pressure. I think the car needs an alignment/bearings or some such thing. It's not a DD and I don't take it over 60mph so who cares. A better way to describe the handling is, "like driving on bowling balls." In my experience, over inflation will exacerbate existing issues. That's almost a good thing... it alerts you to do something about the issue.

Also, I do both the summer treads (all seasons) and the studded snow tires at 50 psi in the 740.

B

[theholycow]

Ah, good point about handling: If your increased inflation affects your handling, definitely back it off until your handling is good again. For me it almost always improves handling, except at 80psi on the rear tires of my pickup with the bed empty and rain on the ground, so I run 60-70psi back there unless I'm towing my camper.

Also, I think I forgot to mention that I think you get more total miles before the tires are worn out even with center wear.

I'm running my studded snow tires at higher pressure right now but once we actually get some snow I may experiment with the recommended pressure instead. Let's hope the weather doesn't give me a chance to find out.

[CapriRacer]

Originally Posted by guest001

Anyone have any comment on long term effects on tires inflating to max pressure? Ie. uneven or maybe accelerated wear?

I have been tracking the reports of folks using elevated tire pressures for a couple of years now, and I think the affect of center wear is a bit more than many people think.

Plus, there have been reports of wet traction issues. Some of these are the result of the bouncing affect, but there are a sizable chunk that are not.

There have been reports of groove wander, impact failures, blowouts, etc. from elevated pressures that seem to be beyond the norm.

Personally, I am not a fan of elevated inflation pressures, but that makes me a pariah aroud here. But I am more interested in understanding what is going on, rather than pushing a particular point of view.

[theholycow]

There's nothing wrong with having a different opinion. It's likely based on different experiences and different observations. If you weren't thinking or researching, that might be less respectable, but I don't think that's how you got to your opinion.

Impact failures and blowouts cannot be caused by overinflation. We're not talking about bicycle tires here. Impact failures happen when the impact compresses the tire until the sidewall is cut by the rim; increased pressure increases protection against that. Blowouts are almost always from underinflation.

I wouldn't mind reading some reports to the contrary, although it's unlikely to sway me from my ~10 years and 350,000-400,000 miles experience with elevated pressure.

I agree with the wet traction thing. That's why it's important to experiment and keep track of your results. You don't just set it and forget it.

The nice thing about tire pressure change is that it's easy and free to experiment.

[FrugalFloyd]

I was forced to buy a new car (2012 Hyundai Elantra AT, 29/40/33 mpg city/highway/combined) in Louisiana during the holidays. We drove at the PSL (80 mph in west TX) for 2 days to get back on schedule, then slowed to 60 mph. I was disappointed to get only 39 mpg that tank. I found an air hose, inflated the tires from OEM 32 psi to 51 psi sidewall max, & got 48 mpg the next tank. 3 tanks highway cruising at 60-65 mph I'm averaging 44.7 mpg in the new car, fully loaded with wife, dog, luggage, & Christmas presents