New Vehicle - Towing Questions

Hi, we tow our 176 with a 2018 Jeep Grand Cherokee with 3.6L gas, with the factory tow package and a weight distribution hitch.  It tows great on flat land, but is underpowered in the mountains where we live.  Mileage is fine on flat land, but fuel consumption is pretty well double in the mountains.  I'd go with the diesel engine were I to do it again.

The Ecoboost engine is one to consider.  We climbed passes many times in the Sierra Nevada Mountains and just drove across the country crossing the Rockies and we had power to spare with our tiny 2.7 Ecoboost engine with very good fuel economy.  That engine needs only normal "regular" gasoline [87 octane].  We are towing a trailer that is rated as a GVW of 4775 lbs. The down side is that there isn't a lot of engine braking on steep descents, but that's true of any small displacement engine.

Originally posted by offgrid Horsepower is horsepower. There is nothing special about diesel horsepower. You will climb a mountain with a 300 hp gasser just as fast as you will with a 300 hp diesel. Low rpm torque has nothing to do with it, you will be running your engine at high rpm either way.

You guys are taking about turbos vs normally aspirated engines. I was discussing diesels vs gassers. Never mentioned turbocharging. Two different topics. So ok we can talk about turbos.

No matter what fuel an engine uses or how it gets it's air, if two engines are each making 300 hp at a specific elevation then they will both proceed up the hill at the same speed. Of course.

Obviously turbos can produce higher horsepower at higher elevations because they compress the air entering the engine. So the air charge can be independent (to a degree) of atmospheric pressure. So a normally aspirated engine will produce less hp at higher elevation than a turbo will, until the turbo waste gate which regulates the amount of exhaust gasses to the turbine wheel eventually can't provide any more boost at which point the turbo power output will begin to fall off as well.

It's not just a matter of adjusting the turbo boost to counter the lower pressure at higher altitudes (called turbonormalizing) though, because compressing the air charge heats it and that in turn reduces it's density. That's what intercoolers are for, they cool the entering air charge which regains some of the power lost to lower density. The net result is that power output typically falls off with increasing altitude in turbo engines too, just more slowly than with normally aspirated ones.

The WW2 deuce and a half had Clydesdales for horses. Modern "High RPM engines" have old gray mares.