Advice on whether or not I should block my grills

I keep 42/40 psi on my 08 GENII and noticed that after 25k, the original Goodyear Integrity is worn evenly on the outer rim (both side of the tire). I was expecting the inside to wear more?

 

Yes it sometimes feels like even 42/40 is 'under inflated', but I do not choose to exceed the safety rating of the tire. I subtract 2 to allow for an inacurate guage then subtract 2 for the backs.

 

Without a scanguage......is there a idiot light to tell if the ICE is overheating????

I want to block the lower grill......but still worried about doing it blind.

 

Sure... check engine light. But by that time... it is probably too late. If you don't block the upper, I am sure you will not have any problems, certainly under 60 degrees.

[edit] - I just double checked and there is a High coolant temperature warning light. See page 548 of the OM for corrective measures.

 

Hi Derek,

No. Its been shown many times on the Prius (at least) the 42/40 psi setting gives more even wear across the thread, avoiding premature tire replacement on the 2nd Gen Prius. We expect to see the same thing on the 3rd Gen. I seem to remember some people have already blown through (more than 40 K miles) their OEM tires, and found even wear at the higher pressures. But, I cannot place my hand on the link. The tires are larger, and the load different on the 3rd Gen, so the optimum may be different. But, its probably going to be north of 40/38 psi.

Wayne Gerdes, a hypermiling commenter at Cleanmpg.com, recommends running the tires at the sidewall max. So, that would be 44/42. He references the web site driver.com, which is a website for police pursuit drivers. Michelin also stresses higher inflation pressures for best hydroplaining performance.

At the higher pressure, the sidewalls flex less, so the rubber does not run as warm (hot where you live). Low tire pressure was one of the reasons the Explorers were flipping over. The sidewalls got so hot, the rubber failed.

Some materials have dramatically different strength at different temperatures. Rubber is one of these.

We tend to think of the car placard pressures as minimum safe pressure. Higher will reduce wear, as the tires run cooler, and the heat conducted into the tread is less, and thus the tread wears less. This jives with the experience of many having the tread next to the side-wall wear down allot quicker than the center of the thread.

 

Looking at the 15 day forecast for Troy, NY I'd say you can block 100% and be OK. You're lows are in single digits at night and highs barely out of the 30s! Depending on your commute and engine block heater might even be a good idea.

- D