Hello all- I wanted to share a "free trick" I recently implemented on my '85 Subaru wagon, the one in my avatar.
Last winter I bought new tires for Subie. Now I'm lucky since it wears 175-70 /13 tires, they are relatively cheap compared to most other vehicles around today. I originally bought this car for a courier route job I had 9 years ago, I needed something good on gas, with lots of cargo room, also good in bad weather & snow. This little Subie is all those things.
My last tire set was rated for 44 lbs. max inflation, so I simply assumed these were the same. I learned years ago to look for higher inflation press. ratings, as this of course reduces rolling resistance, a source of parasitic losses to MPG. I noticed that ratings for max. pressure had increased from 35 to 44 lbs, in some makes/models of tires. A couple weeks ago I finally got down and checked the sidewalls to see the press. rating- and saw it is 51 lbs. I inflated up to 51, using a good press. guage. It drove noticeably better. So-using an old "cheap trick" I tried adding just 3 more lbs. press.,checking cold, of course. Tires should be cold to check pressure, I try to check in early morning before driving and long sun exposure. Heat of course boosts the pressure.
Now this car will roll for blocks in Neutral gear (5 speed trans. I only do this if conditions allow). Ride is only a bit harder, not objectionable. This combined w/ the MPG Remedy, has added better acceleration, and allows some enhanced "hyper-miling" driving styles, though I don't really do so much of that. My local traffic doesn't allow too much of that, though I might put in Neutral and roll down a long off-ramp going to work. Traffic reg's prohibit driving in Neutral gear, and should be avoided w/ automatic transmissions...
So that's my recent experience. IF you're shopping for tires, pay attention and ask about pressure ratings- I was favorably surprised by these tires' rating!!
This free trick of checking the tire press. can make a real difference! Common sense must prevail- tires need to be checked periodically, check and maintain the pressures. The gubmint has been telling us for decades to check the tire pressure, AND condition for safety's sake. Don't go overboard w/this, DON'T try adding 20 lbs. press. to tires rated for 35 lbs, or tires in poor condition!

Use your noggin here, there might be "free" gains available! If tires and all else are in good shape you might try adding a few extra lbs.of preesure over the sidewall rating, checked cold. Compressed air is cheap or free, tire guages are cheap, and the MPG Remedy isnt too expensive to try.

another useful "trick" for Gadgetmen to try!
Tracy G