help with my drive tire choice

Is my operation as I present,, is it a perfect world in trucking as an independent O/O? Perferct weather and roads? My RR comes from the Michelien site and my data shows the improvements. My 1st truck purchase was in 1980 a 1975 Ford 318 det. I do not buy snake oil and I believe in Show ME and I want to know who they are we they say bla bla bla. Im running my truck for .80 per mile, I can show you, can you?

 

Epmtrucks:

You have at best a 13.7 % increase in fuel economy from 6.5 to 7.39 and at worst the increase is 8.7%, from 6.8 to 7.39.

You're driving 61 now, how fast were you driving before?

 

The same speed. The sweet spot.... I even went to tall rubber 3 years ago. 1600- 1650 rpm. Im still conflicted if I dont have a 13 sp direct drive. Any help is welcome on helping me determine. 1600 rpm 13th gear, 3:55 rears on 24.5 tall rubber gps speed 60 mph

 

10% fuel savings in my operation is $5000.00 per year.

 

An average 11/24.5 has a tire revolutions per mile of 471 so:

471x3.55= 1672 rpm @ 60 mph.

1600 rpm @ 60 mph would mean a .96 overdrive. That's pretty unlikely.

I'd say you've got a direct transmission.

 

My tach and seedometer are cable, but I know the gps speed is correct. Im very confident the tach is accurate. The truck has a 350 hp economy 3406 B Cat, built to compete with the formula Cummins in 84. Im thinking the engineers knew that direct 1:1 transmissions where the most economical. They are starting to go back to that today. Thanks for the math lesson!

 

I'm not arguing that you did not see an improvement. I'm just stating my opinion that I feel the RR numbers are a bunch of propaganda from tire manufacutrers is all. I run a Western Star Lowmax (shaped like a brick) with 3.55's and a 13spd and LP22.5's.... At 60 mph I see 1325rpm, which is not my sweet spot at all. I ran that speed for about 6 months and was able to gain alomst .25mpg by bumping it up to 63mph which puts me around 1375rpm. I'm getting your same MPG numbers with my high RR M726EL's... that's all. Going by the Michelien's data, i should be doing far worse than you.

 

All vehicles and operations differ, and your most important fact is the DRIVER!!!!! The data as shown in my operation shows a very measurable improvement. By year end I will a full 2 1/4 years data in which I have noted the dates when different changes where made, weights, weather conditions & fuel stop locations. Same truck, same route for 2 years on paper, no fudging or what ifs, just what is factual, should help me determine my future tire purchases, other maintenance purchases. Its an apportunity that seldom happens for an independent. And since Im so light to TX, I may try a lift axle on the trailer.

 

You might try the bridgestone 710 or the xda energy dual tires. If its the same money why not. A new tires RR is going to improve with proper wear.