Power Loss @ Elevation

[DougIrby]

I've been researching this topic and it seems that normally aspirated engines, like the ones we have in our Silverados, loose 3% of their power for every 1,000 feet in elevation gain above sea level.

 

When driving in the mountains of Colorado this can mean we loose over 100 horsepower at elevations aproaching 10,000 feet. That is significant, especially when towing up a grade with a trailer.

 

Engines that have forced air induction, like the Ford Eco Boost, do not loose hardly any power at higher elevations, from what I read.

 

What to you folks thing about this information?

[Justin101714]

Sounds normal to me. The MAP sensor and barometric pressure changes will affect the way fuel is delivered as well.

 

 

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[Silverado Steve]

Sounds about right and one of the main reasons Ford touts the Ecoboost amd one of the primary reasons diesels are used more often to tow than gassers here in Colorado. Check out fastlane truck videos on Youtube where they compare the Ford ecoboost versus the 5.3 and the 6.2 in a towing mashup.

[2018GMC]

You could always add a supercharger. :-)

[2018GMC]

You are correct on elevation and hp and tq loss. I live at 7k feet elevation. Whenever I take my truck down to 1k feet elevation, it feels like I gained a cylinder or two. Then once I'm driving back up the mountain you can feel the power loss.

[Colossus]

Welcome to life in Colorado

[truckguy82]

If I lived at a high elevation I would only be buying cars with turbos. Turbos have a goal of reaching a specific manifold pressure. So if the atmospheric pressure at high elevation is 2 psi less than sea level, the turbo doesn't care, it's going to spin until the manifold sees whatever pressure it was set at. You can do the same with a supercharger, but you'd need to install a smaller pulley to compensate for the elevation, it doesn't do it automatically like a turbo.

[DougIrby]

You could always add a supercharger. :-)

 

I've been thinking about doing this. It's expensive, so I have to wait until I get the money to do it.

 

I was wondering how the resale value of my truck would be impacted by a supercharger. Anyone have an idea? Would it be a foolish thing to do, financially speaking?

[diyer2]

This is a FACT.

IMO

The computer see's less oxygen for combustion and leans the fuel mixture = less HP.

Oxygen loss is the same 3% per thousand I think.

Temperature also affects the density.

Google it.

 

[truckguy82]

This is a FACT.

IMO

The computer see's less oxygen for combustion and leans the fuel mixture = less HP.

Oxygen loss is the same 3% per thousand I think.

Temperature also affects the density.

Google it.

 

Its not less oxygen per air content, the air is just less dense at altitude. It's essentially just a pressure drop.

 

The atmosphere at sea level provides us with 14.7psi of pressure, go up in elevation, and that pressure is reduced. That's all it is, and with reduced pressure comes reduced density.