28' 1981 Excella- Isuzu Diesel RPM's?
 

I recently acquired a 28' 1981 Excella motorhome. It has the original Isuzu 5.9 with 60K miles, when I got it. I've tightened things up and taken two long trips (2K miles each) and I'm hooked!!

I was running 2600 rpm's at 57mph, getting 12.5-13 mpg. My question is, does anyone know what RPM's this motor is happy with? I'd like to run at 2800-3000 and go 62-65mph from time to time, but don't want to push the motor too hard. Any advice on this rig and motor would be awesome!

Thanks!
Jeremy

Nice looking RV!

I recommend you repost in this section, where there is more traffic-

https://www.airforums.com/forums/f311/

The section you posted in here doesn't get a lot of traffic

I run my Isuzu between 28 - 2900 rpm at about 62 mph. Seems to be a sweet spot. I keep it under 3000 always. We’ve put around 40,000 miles on the rig running at those numbers without issue.
Mike

Welcome to the forums and to the world of Airstream moho ownership. You have joined a rather interesting group of people.

Your Isuzu will be quite happy running 2800 to 3000 rpm. Mine did so for many miles. I on the other hand was not so happy. I installed a Gear Vendors overdrive unit. It brings the rpms down and gains some road speed. 2300 to 2400 rpm provides 63 to 65 mph. Now the Isuzu and I are both happy.

Thanks Dan! I was checking out the gear vendor gear splitter as well. Have you ever towed a vehicle once you installed the spitter? I was curious if this would give me the power to tow while keeping my RPM's reasonable at 55mph.