Drivers with Higher Tire Pressure

[popennell]

I've been mulling around the idea of increasing tire pressures slightly, but I've had this nagging voice in the back of my head that says, "if it was a good idea, Honda would have done it." I'm curious about you folks who've been running higher than suggested tire pressures.

1. How much more pressure are you running?
2. How many miles have you been running over-inflated?
3. Have you noticed any unusual wear patterns in the tire normally associated with over-inflation?
4. What kind of a difference did it make for your fuel economy (roughly)?

[Tinytimmy80]

1. 44 psi all-around
2. 18.000 miles now
3. The standard Dunlop tires are total crap. I had to replace the two front tires after only 15.000 miles. They were almost slicks. The wear was even though, so overinflating didn't have a negative effect. I had to replace one rear tire because there was a huge nail in it (noticed the flat after about 40 miles, so the tire was toast).
4. Not sure, at least a few mpg's, especially on the highway.

[Purplegate]

1- 46 to 48psi all around
2- over 20,000miles (was at 42psi before)
3- It seems to have actually helped. I'm at 35K miles now and still running fine on the original Dunlops. Most of my driving is on highway though, so probably quite uniform surface most of the time. (I still percieve the OEM Dunlops are a poor tire and look forward to change them...)
4- I would estimate ~6 to 7mpg

[popennell]

Thanks guys, I've been a little reluctant to do it for fear of uneven tire wear. I didn't want better fuel economy at the expense of shorter tire replacement intervals or the infamous "wah-wah-wah-wah" you get when the tire starts cupping or feathering.

I've got a road trip coming up tomorrow evening, maybe I'll try to convince myself to put some more air in the tires before I leave town...

[zurk]

i put 35psi in mine. i wouldnt go over 40psi. ride is too harsh and tire wear is not worth it.

[mank]

I run my tires at the recommended 32 PSI. I have 11,000 miles on the Dunlops and I don't see any wear at all yet.

Just my 2 cents worth.

[Tinytimmy80]

Let's make one thing clear: over inflating your tires does NOT increase tirewear. The reason why my tires wear faster is because I probably take corners too fast. In Europe people drive a LOT faster than in the US (not that I am proud of that fact).

I was amazed at how sloooow traffic is going when I visited the states. It's one of the reasons why we (Europeans) don't understand why Americans like their 4.0l V8's/hemi's so much.....
Ok, in mountainous terrain it's nice to have more power, but in the city it only wastes gas and makes noise.

[Cobb]

I run the sidewall psi. I got about 30 thousand from the stock dunlops. I didnt get them rotated as frequently as I should of, once every 5k miles.

The tires were bald all across the surface, no wear focued on the outter edges or just down the middle.

I run sidewall psi on all my vehicles.

[MN Driver]

In the United States, most drivers don't know how to keep a decent following distance and most of the issues come up with people who want to change lanes or merge onto a high speed road and the following distance isn't there or the driver who is merging doesn't know how to plan their way onto the road. ...which is a HUGE problem where I live, in Minnesota. It seems to be a constant expectation that if someone is merging onto a road that the driver merging can accelerate onto the road at 40mph and force anyone in the slow lane to move over so they can get on the road. The problem is that the same behavior occurs when the next lane over is occupied forcing the driver already on the road to slow down rather than the person entering the road to share that burden.

With getting off the road traffic is slowed down because people don't allow others to merge, typically a 'road politics' kind of thing where someone thinks they are cheating to the front of the line but in the end if there was enough room for them to squeeze in before the chokepoint ahead, they probably would actually move in which would speed everybody up who is waiting in the single file for everyone up front trying to merge.

Unless you are talking about the 90-130km/h speed limits here on our highway/freeway/interstate roads, those are a bit slower than Europe.

As far as large engines go, I think its the power people are attracted to and the ability to merge and show off their cars. The media here portrays the 'bigger is better', whether it be the 'news', ads, or friends. Its the land of excess and waste here. I'm not proud of it but unless you are being wasteful, reckless, or making fun of something that is actually better, you face judgement. I get it often with my car(1st gen) due to two seats, small engine, and that it doesn't roar like every other car down the road but it fits the needs perfectly for me and uses so much less gas. Once I explain it to people they put down their United States 'bigger is better' mentality for a second and start asking questions and they usually learn something. I think the others will learn when their <20 MPG car slaps them in the face but then they will forget quickly once gas drops a dollar from its previous high. It seems that people who got slapped with $4+/gallon gas are figuring it out again now that we are around .50 cents from where we were in the middle of 2008 when crude hit record highs. The hardest people to ever convince that their gas guzzler is a bad choice are the ones that believe that their car gets them women. Whether or not its true, its one very expensive way to do it when you do the math. I have a feeling their mentallity doesn't change if/when they actually get married. The herd is stupid in general, no matter where in this world someone lives, but there will always be a decent 10% of people who either are smarter than the rest or will be able to figure it out and not forget.

I'll answer the questions
1. How much more pressure are you running? If I brought home an I2, my minimum would be sidewall max. I won't post my actual pressures here.
2. How many miles have you been running over-inflated? Since 2006 and with two cars, over 60k with the first car and 18k in the past 12 months with my 1st Gen Insight.
3. Have you noticed any unusual wear patterns in the tire normally associated with over-inflation? No, my wear patterns are pretty much normal. Sidewall wear from hard cornering was reduced when I raised pressure. At the end of life my tires have been within 1/32" across the tread. I swap front to back and do not cross sides because of this consistent wear. Also much easier since I can jack just one side up to do it since I do my own automotive work. My tires seem to wear quite a bit less now that I'm not running 30-something in my tires. If it weren't for hard cornering that comes with using less brakes, I have a feeling my tires would last quite a long time.
4. What kind of a difference did it make for your fuel economy (roughly)? Not sure with the Insight because once I got it home from Wisconsin its first stop was my air compressor. With my 1995 Geo Prizm the difference was low 30s on a decent summer gas tank to very high 30's and bottom of the 40's. This is with a car EPA highway rated at 34mpg. I got 40-44mpg driving 75mph on the interstate over multiple tanks with that car with higher than stock inflation and a few work commute tanks of 43mpg. Now that I have better hypermiling skills, I think I could manage 45+ mpg on that little thing but I'm getting ready to either overhaul the ring pack on that Prizm or decomissioning it due to excessive blowby pushing seals out since the PCV system is too overwhelmed to do the job, common issue for that engine.

[freddy the mug]

I have been running the stock dunlops at 48 psi for the past 5k miles and the tread still looks excellent at 12k miles. Rotated tires at 10k. Handles impressively well. When I get around to it I'll try 50psi.