Hi All,
I've got a 05 4WD stick. Only had it for a couple o' weeks.

My current in-town MPG ranges from 15-17.5 non-towing. Now, this is real good to me since my 90 2500 Vandura gets about 8 MPG in town.

But I've noticed the MPG is lower when I shift at higher RPMs {expected}. So, I try to keep the RPMs down and get better mileage. However, I don't want to "lug" the engine.

IS there a rule of thumb on how low the RPMs can be per gear?

 

generally, i've heard 1600 as the cutoff. However, if you ask me, the easiest way to tell if you are luggin a motor is to listen to it. try to accelerate from about 5 mph in 3rd gear .. you will hear the distinctive sound of the motor lugging. It is one thing to cruise at 1100 rpms in a high gear, but if you need to gain speed, you have to downshift. Generally Id say as long as you are keeping the rpms above 1100 and not hearing the lugging sound, if youre not towing anything, youre good.

 

Thanks,
BTW, what 'damage' is caused by lugging the engine? Besides, lurching the heck out of the truck.

 

Your CTD produces peak torque at 1600 rpm, so I would think "lugging" the engine would occur at a speed below that.

 

Thanks, buit whats a CTD

 

Cummins Turbo Diesel....