V6 or 4C for Colorado Mountains?

Windsor is about 600 feet. Ottawa about 300 feet. Denver is 5,280 feet (mile high city) and everything that is fun is at 7,000 to 10,000 feet in elevation

And yes. larger sized tires will reduce torque and power to the wheels and worsen any issues that altitude will add. Most of the good off-roading in Colorado is better served with oversized tires (increased clearance). Especially with the longer wheelbase of a 6-0 bed.

 

I own a 4 cyl and it was perfectly adequate for the mountains. That being said, I think the manual transmission is a must. Multiple times a year I would drive over the mountains from Grand Junction to Denver, and my truck was always capable of the speed limit. I would have to wind the engine in 3rd gear to climb Vail pass, but I could hold 70-75 uphill the whole time. Many of those trips were with camping gear and an Old Town Canoe on the roof. You're not going to win any races, and you will have to shift for most hills, but the truck will work fine hauling a few hundred pounds of gear all around the mountains. The 2.7 is a workhorse, and if money is a factor, I think a viable option for a Light-duty Pickup truck.

 

Turbos were invented for that very reason... To compress the thinner air so that air plane motors could get better combustion.

 

World War 2 airplane engine swap instead of a forced induction computer controlled drive by wire Toyota engine?

That would be a very cool swap but it would mean giving up some bed space and probably having to have a new frame custom built.

Pass the idea along to one of the television reality shows.

 

Agreed, which is why I desperately miss my WRX turbo, well not the breaking down part. If I was going to buy a new truck, I'd actually look at the Chevy Colorado with the turbo diesel option. That would actually be BEST in the mountains. The V6 can handle 10k feet with all my camping gear and 33s, but it's not that fast, and looses quite a bit in the mountains. I'd prefer a turbo.

Oh, while we're talking about it, supercharging doesn't have the same effect. It will still lose horsepower at elevation, where turbo will not lose power. You will have more lag/delay in achieving boost, but once you hit boost there is no power loss.

 

Honest question, why doesn't a turbo lose power at elevation, while a supercharger does? I've never heard that before, and it's not intuitive to me...

 

any IC engine loses power at high elevation- it's a scientific fact based on available oxygen. I've driven a turbocharged car at high elevations and it also greatly suffered. But if you have 300 HP maybe you go to 200 where 150 goes to 100.

 

No, turbo does not lose power once it reaches boost at elevation. Though it may take longer to reach boost.

Turbo: Freely spools off exhaust gas pressure, at elevation air is thinner, thus it will take longer to "spool" the turbo to reach full boost pressure. Once you have reached full boost pressure, you are making full power. On my WRX the lag at elevation was pretty negligible. Once you hit target boost, you are at full boost until you let off the throttle. Thus you may meet your target boost of 12 psi at 3500 rpms instead on 3250 rpm, but you still hit it and have your usual 12psi to make the same power.

Supercharger: Boost is a multiplier of the air that is available. Supercharger does not freely spool it is tied to the crank by a belt. Thus the boost varies by RPM and will be lower at all RPMs because you have less ambient pressure to start with. Thus at 0 feet elevation you may make 6psi at 3500rpms and 8 psi at 6000rpm, but at 10000 feet you may make 3psi at 3500 rpm and 4 psi at 6000rpm.

Thus supercharger loses power at all rpms at elevation, turbo only has more lag.

 

That would apply only if you had such a poor or broken setup that the turbo could not spin fast enough to make full boost. Like if you had a large v8 which requires a large volume of air and a very small turbo charger. This is not the usual case with most turbo cars.

Yes there is less oxygen available, but most turbochargers are able to get enough air to make their usual set target boost, and once at full boost make the same power. Again, this is why airplanes with combustion engines use turbochargers.

 

I agree that in theory it's possible that a turbo engine won't lose power at elevation depending on controls and having a large enough turbo. but
10 psi boost at sea level is 10+14.7=24.7 PSI
10 psi boost at 10,000 ft is ~10+10= 20 PSI

Theoretically a turbocharger in the second example can make more boost to make up another 5PSI if the controls allow it and the turbo is large enough to move 30% more air. But then you have a 30% larger turbo than you need at sea level and the car is laggy there.

The car I mentioned developed 10 PSI at sea level, and elevation, and had a noticeable loss of power above 10K ft. It had a slightly larger turbocharger than factory (Mitsubishi 16G vs 14B) and a sound 2.0L engine.

 

Same here...live at 6700 ft, drive mountains frequently, have a topper and a manual tranny. More than adequate for my use, but I would be reticent to tow anything larger than a small utility trailer.

 

I second the comment about trailers. I have a 4x8 trailer that I rarely tow with a heavy load.

I live in a small town, at about 5000 ft elevation. Any trip out of town takes me to about 7000 ft. I have load range E, 265/75R15 tires and a camper shell and still average better than 25 mpg when not 4 wheeling.

 

I did a quick search and found some data re turbos and loss of power at altitude. There is some good info in the replies, especially #8- he also mentions the computer additionally decreasing boost because of elevation which I thought was interesting. If you want sea level power at 10K feet it's possible- but you need a big turbo, custom engine management to increase the boost, and sea level premium octane fuel (93).

https://forums.nasioc.com/forums/showthread.php?t=428218

 

turbos will noticably lose power at altitude. This is true of any engine, turbo charged, super charged or normally aspirated. Thats why on aircraft we specifically design turbos and superchargers for various altitudes.

Im not saying one will work better than the other. Im just saying that the broad stroke statement that a turbo charged engine will not lose power as altitudes changes without serious design modifications is simply not true.