Different gear ratio MPG around 78 miles per hour

The other one got locked because it was going no where. Wouldn't be surprised if this one went the same way

 

The amount of variables we're dealing with here are astounding. You probably aren't going to find an accurate answer.

 

If you wait a while as in a day or three you will find that it becomes more productive over time. There are some very good people who are actually working 14 hour 600 mile trucking days and not here at the keyboard at our beck and call to quickly answer something.

Just rest easy and let the topic or question soak in the pond a little while the fish will start biting when they come along and see it, plus provide answers or in general a idea how you or anyone can get closer to the solution, whatever it is.

In the end of the day Whatever gear ratio on the tractor's final drive axles and whatever your transmission is and engine and so on can be mutated 10,000 different ways for different purposes. There are websites that sometimes provide Ratio calculator to get close to the idea that you will know ballpark what ratio is under your drive axles.

Ive liked mine at least 3.40 in big rigs. If the top end is too runt, add gears or a second box aux until you have enough to get up and run 85 or whatever without straining everything back there.

Ive had way too many seriously #### company rigs with like 2.40 or so and unable to stay in top gear at 60 without having to saw the thing against it's governor that low. I once quit a company that set it at 60 totally ignoring the fuel burn and inability to hold 60 as a means to cause the driver to wear himself out, potentially breaking the truck from constant sawing of gears and destroy any savings to fuel. Not to mention the 2.40 or so gear ratios are inadequate and forms a wall against the engine which now has to WIND all day before you can be assured of keeping the next gear up.

 

Ok thank you. I was away most of today and was not aware of it's demise. Im just going to help out a little where I can with what little I understand. Trying to Encourage the OP to just let it take a time. Maybe a day or three. People will be along sooner or later. We have alot of people here who knows a great deal about transmissions and rear ends.

 

...just be gentle with your right foot

 

You will get 4.2903 mpg with any combination you can think of. Happy Truckin!

 

It is not the transmission it is the Rears.

You need the right ratio in the rears to do what you're talking about.