I am extremely happy with 40+ PSI, in terms of ride, handling, and fuel economy. When I corrected my tire pressures after they had been apparently lowered by the dealer during servicing, I noticed a big jump in mileage. (Not sure how much of this might be attributed to the oil change.)

I underscore lars-ss' advice: do a search of this site for comprehensive info.

Don't forget to reset your tire pressure sensors when you adjust pressures.

 

there is no consensus here. Some swear by adding 10+ psi upwards of 45PSI. Others say 40. I like to erro ont he side of caution, I have to beleive that 45PSI is casuing less tire to contact the road and thus I feel it is unsafe. I run 3-4PSI over to allow for some natural loss of pressure and minimal loss of contact with road. There is a reaosn the car maker sates a certain PSI. Regardless of the "slightly harder ride" which they could compensate for in suspension they spec 32 for a reason, if the MPG benefit were that great with no loss in saftey I am sure when gas was $3 a gallon they woudl spec 40PSI or 45PSI. I read and article a while back where they interviewed a Michelin engineer who said use the MFR number, but in general it is better to be 3 over than 5 under. Why did he only mention 3? beats me, but if it were that safe to be 5 or 10 over I am sure he woudl not have compared 3 over to 5 under! We all take responsibility for our actions, I have decdied I will be responsible for me and my passenagers at 3-4 over, I won't risk hydropaning or a smaller contact patch for 1-3 MPG. If my life were worth the extra MPG I would sacrific comfort over saftey and get a Prius first and get 8-10 better MPG.

OK I stepped off my soap box...

 

The major reason manufactures recomend a certain psi is that it gives the most comfortable ride. This is probably why certain luxury vehicles come off the lot with under inflated tires. The dealer wants to sell a car so they lower the psi.

They could compensate for the ride by improving the suspension, but if I were to build a car and I wanted to make money why would I put a lot of money into a suspension when I can just lower the recomended PSI by 5 PSI? Financialy it doesn't make sense.

BTW, hydroplaning goes down with over inflated tires, stoping distance shortens in all instances except stopping in the snow. These are things most people make wrong assumptions about.

 

If we have another drawn out and tired re-hash of the pros and cons of tire pressures, I think I'm gonna puuuuuuuuke. New info only, please!!!

 

Heh. There is no new info. This has all been discussed many times

 

Maybe we have found a cure for Acute Dire Warning Syndrome!

 

The major reason manufactures recomend a certain psi is that it gives the most comfortable ride.

Is that comment documented somewhere. I assume it is since it's the MAJOR reason manufacturers do it. I can't imagine with all the Millions of $$$$ that GM and Ford spend to up their corporate milage figures that they would walk away from another couple of tenths of mpg just to make the car more comfortable. maybe to a point of compromise but not to a point of ignoring FE over comfort. Their rating has to be something safe they can stand behind as well as the nu,mer they use in testing the car. A person can always lower the pressures to make a car more "comfortable". However with the TCH I see comfort almost as a non factor. The car is sprung so soft I don't imagine it's a rough ride even with foam filled tires (I;m surprised some of you have not done that (maybe can't figure out how to balance them that way?)


stoping distance shortens in all instances except stopping in the snow. These are things most people make wrong assumptions about.

That's a pretty broad statement to make. I can't imagine a TCH stopping shorter with 45 psig in the tires than when set at the recommended 32. There may be an optimal set point somewhere above the mfgr recommendation, but it's certainly not "unlimited".