350 HP ICE vs. 350 HP Diesel?
OK, newbie here and aspiring RV'er. What comments can be made about the advantages/disadvantages of a 350 HP internal combustion engine vs. a 350 HP diesel engine in a class A camper (assuming all oth...
Forum Discussion
Summary, CI (diesels) engines cost more than SI (gasoline) engines to build (buy) and maintain. Though performance is better at higher altitudes, there is little else to be gained. Past that, the differentiation can only be established by a complete economic analysis of each specific situation.
I don't think very many people here will like what I have to say, but the problem is that what I am about to say is fact. If you don't agree, you are free to do the research and post it here..
The biggest difference in CI vs SI over the road engines is very simple. Diesels(CI) do well with turbo-charging and spark ignition (SI) engines do not. I could get down one of the papers I wrote on this, but I don't have the time.
The simple answer is that air is what makes horsepower. Horsepower is Horsepower and I don't care where the torque peak is, gears can fix that. The reason air is important is that it is needed to burn the fuel (any fuel) to make horsepower. Turbo-chargers are an inefficient way to cram more air into an engine. The advantage that they have is that they are not dependent on the engine crankshaft speed to do this. They also exhaust into the local atmosphere as so they can increase the manifold pressure as altitude increases. This is a real advantage at altitudes above 8K MSL a turbo-diesel may (depending on calibration) have a significant advantage.
Another serious comparison has to be cost. CI engines cost more for lots of reasons. Maintenance costs of many CI engines is higher that most most SI engines. (This is a gross generalization, but typically accurate.) Over the life of a typical RV the fuel savings will never overcome the combination of initial cost and the differential cost of maintenance. This can only be determined by a complete cost analysis.
So, do the complete analysis and make your own decision what will serve you best.
Me, What do I know about this??
I ran contract engine testing laboratories for about 30 years.
I am a ship's engineer by trade and have owned 6 diesel vehicles.
Matt
I don't think very many people here will like what I have to say, but the problem is that what I am about to say is fact. If you don't agree, you are free to do the research and post it here..
The biggest difference in CI vs SI over the road engines is very simple. Diesels(CI) do well with turbo-charging and spark ignition (SI) engines do not. I could get down one of the papers I wrote on this, but I don't have the time.
The simple answer is that air is what makes horsepower. Horsepower is Horsepower and I don't care where the torque peak is, gears can fix that. The reason air is important is that it is needed to burn the fuel (any fuel) to make horsepower. Turbo-chargers are an inefficient way to cram more air into an engine. The advantage that they have is that they are not dependent on the engine crankshaft speed to do this. They also exhaust into the local atmosphere as so they can increase the manifold pressure as altitude increases. This is a real advantage at altitudes above 8K MSL a turbo-diesel may (depending on calibration) have a significant advantage.
Another serious comparison has to be cost. CI engines cost more for lots of reasons. Maintenance costs of many CI engines is higher that most most SI engines. (This is a gross generalization, but typically accurate.) Over the life of a typical RV the fuel savings will never overcome the combination of initial cost and the differential cost of maintenance. This can only be determined by a complete cost analysis.
So, do the complete analysis and make your own decision what will serve you best.
Me, What do I know about this??
I ran contract engine testing laboratories for about 30 years.
I am a ship's engineer by trade and have owned 6 diesel vehicles.
Matt
