Autos vs Manual transmissions

You're comparing a group of company drivers who by and large do not give a rats behind what mpg the truck gets, how much fuel costs, or even if there is enough oil in the engine. Stomp on it and go. For the fleet with drivers like this, automatic makes total sense.

For the independent or very small fleet the manual will last longer, and get comparable fuel mileage. The driver has more control. There is no computer malfunction possible. Does the gear go in at the correct rpm or does it not? No questions. Also these trucks are often kept well past the end of the warranty period where the large fleet has a trade in cycle often before warranty is up. It is unlikely either auto or manual will cause a major headache under warranty. When you get out to 700,000 miles and beyond is when they act up and cost more to repair or replace than it saved in mpg and maintenance. Teaching a driver how to shift is not something a trucking company is supposed to be doing anyway. What is school for?

This is an apples to oranges comparison.

 

Okay. But I'm not an idiot and neither is our upper office. Obviously nobody is referring to the truck computer estimated mpg. They only look at actual fuel consumed (bought) and compare driver against same driver (same driving style)

A year ago I was anti auto too from a fuel consumption standpoint but I think Detroit has about figured it out.

 

We have a driver in a 2017 Peterbilt 567 with 500 hp Paccar MX-13 and 18 speed manual getting 6.65 mpg in the mountains in British Columbia pulling 137,500 lbs gross on B-trains.

An autoshift Peterbilt 579 with 455 hp MX-13 is getting less than 5 mpg with 100,000 lbs gross on tridem in the same region.

Tell me again how much technology contributes to fuel economy.

 

@Zeviander

Did your company train the driver how to push the button correctly in the automatic? Maybe he is pushing it too hard, that’s the only possible explanation an auto would get worse mileage! LOL.

 

LOL

Nah, I think it has more to do with the MX-13 being a bag of crap in the hills over 80,000 lbs gross.

 

Same driver? Same gear ratios on the diffs? Same runs (same grades, flats, etc)?

 

Different driver, but all the ones in the 579's are senior drivers with proper feet (no heavy boots). And different weights on the same route.

 

The reason I'm asking is this:


Trucks of different types are omitted. This is our actual mileage report from November. Same exact trucks, all specs matching. Only difference is the drivers. A driver can make the difference, but you also have to factor in we all do different runs, different loads, etc.
Oh, and these are all DD13s with the DT12 transmission.

 

The company I work for has Diesel and CNG's. Have you driven a CNG yet?

 

I've seen them, dont know a lot about them. What can you tell us about them?