Tire Pressure

psuinsight · 06-14-2006, 05:05 PM

I finally got around to buying a tire gauge today so I could check my Insight's tire pressure. I have been averaging about 56 to 58 mpg with the tires at the pressure provided upon delivery from the dealer.
Unfortunately the pressure was - front tires 38 psi, rear tires 32 psi.
I plan to fill up my tank (last gas visit May 17)

and pump up my tires to 42psi, front and back.
I will report back on my future gas mileage with pumped up tires.

Insightful Trekker · 06-14-2006, 05:33 PM

the tire sidewall rating for the OEM's is 44 psi

But expect a harsher ride and a bit easier skidding in emergency conditions. Many hyper milers go to 50 psi.

The difference between your front to back "average" of 36 and increasing to 42 may not be sufficient to definitively see. But it will be there at the pump.

HTH!

psuinsight · 06-14-2006, 05:50 PM

Thanks, John, for the info. Maybe I will just go ahead and inflate to 44 psi. I am a bit reluctant to exceed the tire's rated pressure, although there is probably a corporate policy to rate tires below any actual safety point. I usually pump my bicycle tires above the rating and have never had any problems. Bike tires no doubt encounter much less stress than auto tires, so that may not be a good comparison.

Resist · 06-14-2006, 07:29 PM

Many of us (including myself), use a tire pressure of 50psi in all tires. From what I understand the tire is actually safety rated higher than that. And no, they didn't stamp that on the tire. I used 50psi when I did a cross country trip in my CVT and averaged 60mpg for 2,000 miles.

I doubt though, should a tire blow out at speed with 50psi will anyone warranty it.

Kevin Dougherty · 06-14-2006, 07:48 PM

Higher pressure will also increase tire mileage by decreasing edge wear on the front tires.

Insightful Trekker · 06-14-2006, 10:09 PM

Good points Kevin and Resist.

IIRC a tires blowout PSI is 300% of rated sidewall inflation. However, dynamic forces when driving (pot holes etc.) can more easily pop a tire that is over inflated vs. one that's not.

Kevin, thats the key question with the OEM's. There are conflicting credible reports by Insighters that they experience outside edge wear regardless of how much over inflation. And others report "normal" wear with mileages exceeding 80,000 although not all reports state their chosen inflation pressure.

For me I've got slightly over 40K on my second set of OEM's and both outside edges are worn to the tread wear indicators.

I inflate to 50 psi and the wheel alignment is _perfect_. So maybe its my driving style, but I know how to get ultra miles out of a set of tires

I managed 180,000 on a set of Michelin LX1's on a CRX HF. Or its the _over inflation_ and something in these LRR tires design that causes wear _opposite_ of what is _normal_ for such pressures

Is there any member in here that already _knows_ how to correctly read tire wear from experience (you know who you are) and seen anything to explain the differences

My only conclusion is that the reports of wear being "normal" are from those inexperienced in judging tires or its the over inflation _causing_ wear opposite of what should be expected (my case).

Scott · 06-15-2006, 08:36 AM

If a tire were to blowout at speed while inflated to 50 psi, how would anyone warrantying the tire know what it was inflated to prior to blowing? I personally wouldn't offer that info if it were me. I would simply tell them the tire was inflated to manufacturer's specifications.

kari · 06-15-2006, 09:26 AM

when I pumped my tires up to high 40s I noticed an immediate gain of several mpg.

I know that some people here have mixed reviews of these:
http://www.garage-toys.com/tireminder.html
but they have been very helpful for me. I just have to glance to make sure my tires are fully over-inflated!

spacebug · 06-16-2006, 12:06 PM

Has anyone tried the LED indicator caps that flash when the pressure drops 4 psi from where it started? They look like a good option for those running at higher psi than the 40 psi tire minders max out at.

If no one else has experience with them, maybe I'll get a set and be the test case!

Resist · 06-17-2006, 02:59 AM

Quote:

Originally Posted by Scott

If a tire were to blowout at speed while inflated to 50 psi, how would anyone warrantying the tire know what it was inflated to prior to blowing?

They would be able to tell if they examined the tire and rim. So the evidence would be there and lying about it probably wouldn't be wise.