Which Tires Wear Fastest-The Fronts or Backs?

My Dunlop Ensave 01 A/S 91S tires experienced minimal wear over 50,000 miles. I have been rotating them every 5,000 miles in the correct front-to-back and rear-to-front-crossed pattern.

That said, after getting multiple nails, I replaced them with a whole new set. I am keeping three old tires as spares in case I encounter nails again. One of them had too many nails to be repaired.

Last but not least, I inflate them to 43/42 psi front/rear. That reduces wear and significantly improves fuel economy. My actual lifetime fuel economy without using electricity is about 65 mpg. I think the Gen 4 Prius Prime PHEV is the most fuel-efficient car ever built, more so than the Gen 4 Prius Eco HEV and the Gen 5 Prius LE HEV. Even though on paper it has marginally higher aerodynamic drag than the Gen 4 Eco, it seems lower in practice due to reduced ground clearance compared to the Gen 4 Eco.

 

When I first got my gen 1 (at around 125,000 miles and still quiet as a vault inside) and discovered PriusChat, I experimented briefly with pressures that high, as advocated in the forums.

What led me to call off the experiment was the ride discomfort and the new dashboard squeaks and rattles that developed. I backed off to a compromise like 38 front 36 rear, still above the factory spec but not quite as hard. That fixed the ride discomfort, but not the new squeaks and rattles, which I had to put up with the rest of the life of the car.

 

Well, the squeaks and rattles probably resulted from aging, not the tire pressure.

 

What struck me was that the car was so quiet when I bought it with 125,000 miles on it, and then 'aging' created all those squeaks and rattles so quickly when I experimented with the tire pressure advice.

 

Yep; the higher the tire pressure - the harder the pounding/shaking on all the car parts. Old plastic and rubber components will start cracking and falling apart, because of the consistent road pounding. So it seems natural that things would shake loose vs a softer rolling OEM tire pressures. It's the difference between using a solid tire dolly vs a pneumatic tire dolly. The solid tire dolly will handle a lot more weight without load shifting; but the pneumatic tire dolly won't mar hardwood floor surfaces.

 

I would have thought pneumatic (air filled) tires were more prone to flat spots.

 

Very high pressures can also cause premature shock absorber/strut failure.

I use higher than manufacturer pressure for cornering characteristics, but moderation helps.

When I was a lot younger, I had an MGB. The carburetor could be set very lean, get good mileage but provide meager power; it could be set very rich, provide good power and smell great. Misers would run them very lean, and people looking to squeeze out another half HP might run them very rich. However setting them moderately provided 80% of the benefit of efficiency of the too lean tune, and 80% the benefit of power in the too rich tune.

I see an improvement in handling with overinflation, but the marginal benefit in very high overinflation brings costs you are unlikely to recoup elsewhere.