What a difference tire PSI makes

+1
A few weeks ago I had, found out later, some kind of utility knife blade in one of my rear tires. Before it got low enough to light up the tire pressure warning light - I could not get the MPG above 42 or so. I usually average right around 50 or 51 - maybe a skoosh more. When I finally checked the tire it was down to 17.5 PSI!

With the spare on - the MPG went up again into the low 50s.

YMMV

 

I purchased a set of Michelin Energy Saver Tires AS nearly three years ago, 195x65x15.
I keep all four inflated to 44 psi which is max. sidewall pressure listed on the tire.

Now with 67,000 miles on those tires they are wearing perfectly and will obtain
at least a total of over 70,000 miles on a 65,000 miles tire.

I have always inflated my tires to max sidewall pressure on modern tires. This is
a safe pressure when your vehicle is loaded down like ours is a lot of times.

So, in my opinion, for max tire life, max fuel economy, it works for me....