Gas mileage question

Yes, higher compression ratio and taller gearing helps. Higher compression leads to higher efficiency which leads to more miles per gallon.

Depending on where you live and how hilly that is, changing to taller gearing will mean better mileage but it won't pull the hills as well. An overdrive is nice in that you can have the standard gearing for hills and then shove it down into overdrive for the flats and down grade. I use second gear with overdrive a lot in the hilly country here. On the back roads I use second overdrive going down grade to save my brakes.
 
After reading many forum comments about MPG and talking with local club members it seems that 16 MPG, give or take, is common with the standard "A" transmission and head. I have had a 1930 Model A Cabriolet for almost 5 years. It is equipped with a Borg/Warner 5 speed transmission. On a round trip to Vermont (B Head, 5.2 compression) about 3 years ago a very accurate check showed 21.0 MPG. This year I now have a Snyder's 6.1 Head. On a recent 100+ local ride on a rural hilly course a very accurate check showed 20.7 MPG. On the local Interstate 84 my odometer is spot-on with the mile markers. Three conclusions: 1) Yes there are many variables, too many to mention; 2) Overdrive is a plus (Example: at 55 MPH in overdrive my Tachometer reads 2200-2300 RPM's); 3) Higher compression is a plus. And oh, by the way, I have excellent math skills.
 
You must log in or register to reply here.
Back
Top