Tire Inflation, Really?

[theholycow]

Originally Posted by finfin

p205/75 R15 Goodyear Regatta... I just looked and the center wear is mostly on the back tires. I get a tread gauge and report back later.

Ah. A tire that size is rated for nearly 1,600 pounds load at 44psi, probably something like 1,500 at 40psi. That's a lot of tire for a 2,200 pound vehicle, so I think we've found one instance where center wear is quite predictable.

Of course I'd guess that over 60% of the weight is on the front, considering that the center wear was on the rear tires. I'd say you probably won't lose any FE by taking a few pounds out of the rear tires; by the time they're center wearing you've already passed the point of diminishing returns.

[SolidLiquidSnake]

Originally Posted by SolidLiquidSnake

One thing I wonder about is if the psi reading on your door is totally accurate or if you should fill your tire with more air then that to get better mpg... I like to fill mine 5 psi higher, but sometimes I wonder if 10 could be better or if the wear to the middle and lost traction is worth it..

Nice to know, I will bump up my psi a little higher and keep a keen eye on it.

[theholycow]

More:
Pale's Civic's OEM tire size is 175/70-13, and are rated for 1050 pounds at 51psi, while the car's weight is a few hundred pounds more than finfin's Tracker. I suspect that those tires would wear evenly at 55psi.

[palemelanesian]

The tires I mentioned were firestones (fr380, I think). Budget tires, 44psi sidewall.

finfin, what's the manual / door jam call for? Is it different for front and rear? Maybe we should be looking at that and maintaining the difference as we increase overall.

[finfin]

23/23 (psi)