Why do you Cummins guys want more gears
I’ve heard a number of Cummins fans saying they are waiting for an 8 or 10 speed transmission before getting a new truck. Why? Does the Cummins struggle to get your trailer moving from a stop? Or are ...
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valhalla360 wrote:JRscooby wrote:
Best performance, slam hand in door, keep it wide open. Tach drops below 1800? drop a gear, but it back to 2150.
This is why diesels are happier with more gears. That's 350rpm range you are working in. Without lots of gears, you struggle to stay in that range.
Last car I had with a stick, it was common to operate between 1400-3200 rpm running thru the gears. This was just sedate driving not thrashing it.
Yes, newer pickup diesels have been designed to provide a wider range but not to the level of gas engines.
You missed the main idea of what I was saying. The 8V71, Mack, and NTC Cummins where all about the same era. Mack used the high torque rise idea, and did not need to be changing gears all the time. Guy I worked with could not see the advantage of the 5 speed, replaced it with a 13 speed. The OD gave him more top speed, and in theory the much lower low gear would of been better starting the load and working soft ground. But the 5 always started 110,000 on any paved or gravel road. A couple of times off road it would power out, refuse to move, but cable and dozer got it where they wanted it, unload and drive away. The hand with 13 never ran out of power but it would stop with a bang. Drivelines and differentials cost...
Now a quarry had a genset powered by 8V71. Always ran at constant RPM, would not burn as many GPH as mine. A diesel can be set up to use the multispeed, but just because it is diesel does not mean it is.
