Ranger performance at altitude

[Frenchy]

So I didn't bother to read all of this simply because I got lazy and I also live up in the Rockies in Colorado(pm me and we can talk about those details). Stock the truck does just fine compared to others. Before I got my Ranger I had a 2016 Nissan Frontier and it hated the high elevation especially on the steep grades I am on going to and from work. The Ranger handles them like a champ. In the Frontier I averaged about 19 MPG going to work and back. In the Ranger I averaged about 22 stock. Now I have a tune with a lift and bigger tires and I get close to 24. When I am pulling the steep grades I stay in overdrive while others are probably grabbing the lowest gear and doing 100 up the hills(no idead why since they slow the hell down at the top). If this doesnt tell you anything I do what to tell you.

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[Rp930]

It’s a no brainer. Runs great at altitude.

 

[Sandman Ranger]

Tune it.
Runs even better at altitude!

 

[pull string get cookies]

Im coming up to St Mary’s glacier in my Ranger July 10th. We will be meeting up with my wife’s dad in his rubicon wrangler to play around above 10k feet for a week. If you’re still looking at that point I’ll let you know how mine did. I’ve been told with the turbo though I shouldn’t experience any performance loss by livernois due to the computer adjusting for it. I don’t have a programmer on my truck I just asked livernois if altitude would affect anything and they said no.

Turbos tend to have an advantage over N/A engines at higher altitude. Enjoy!

 

[Rviator]

In a nutshell what happens is the turbo spins faster at higher altitudes to make up for the decrease in air density, keeping the air fuel ratio constant. This way the combustion chambers are essentially unaffected by the less dense air.

 

[dtech]

In a nutshell what happens is the turbo spins faster at higher altitudes to make up for the decrease in air density, keeping the air fuel ratio constant. This way the combustion chambers are essentially unaffected by the less dense air.

Not entirely true - the turbo has a single function - to supply boost when it's needed, as far as air/fuel ratio the engine management system works pretty much like a na - fuel injected engine with sensors , calculations and feedback (lambda) loop to maintain the correct a/f ratio.
At altitude the turbo will have to spin faster to compensate for the less dense air - this spinning takes a small amount of power from the engine (compared to sea level) but it's extremely small but does increase linearly with altitude increase. Back in the day of carbureted engines it was a different story - in most cases there was no ability to adapt the af mixture at increased altitudes and the engines ran rich to the point that some would foul plugs and stall out, sometimes folks would lean out the mixture when headed to the mountains.

 

[VAMike]

Back in the day of carbureted engines it was a different story - in most cases there was no ability to adapt the af mixture at increased altitudes and the engines ran rich to the point that some would foul plugs and stall out, sometimes folks would lean out the mixture when headed to the mountains.

or fill up with that heinous 80 octane (or whatever it is) gas they sell in the nosebleeds

 

[dtech]

or fill up with that heinous 80 octane (or whatever it is) gas they sell in the nosebleeds

85 octane is the lowest I've seen and it's not good for most any turbo engine. Many na engines however do fine with it. I generally use 91 in my turbos mostly because the commonly available octane levels in the Denver area are 85, 87 and 91 and often 91 seems to be priced relatively a bit better than 87 is when comparing octane level vs cost. But oil companies love it when more engines today are recommended to use premium and they ain't shy about premium pricing.

 

[bandit67]

Running 87 octane, I ran 80 mph heading west up to the Eisenhower Tunnel in my stock 2019 Lariat, with more pedal to spare, with me and my wife in it (wanted to see how it would handle that drive that I had done many times in my 6.7L diesel F250). The Ranger did not disappoint in the power department.

 

[ch47dmechanic]

I've driven mine over highway 108 through the Sierras a few times...no performance issues that I could percept. Sonora Pass, the highest point on the highway, reaches almost 9,700 feet.

 

[Frenchy]

Running 87 octane, I ran 80 mph heading west up to the Eisenhower Tunnel in my stock 2019 Lariat, with more pedal to spare, with me and my wife in it (wanted to see how it would handle that drive that I had done many times in my 6.7L diesel F250). The Ranger did not disappoint in the power department.

You will be even more impressed when you run 91 in your truck!! I noticed a good enough difference in both response , power and MPG increase(1-2 at best)!!

 

[Andy]

I have driven all over Colorado with my Ranger and i've never had an issue passing people on high passes. Stock the truck was fantastic and with the truck tuned running 91 and e50 its a rocket. Just last weekend I passed a long line of campers on Wilkerson pass reaching triple digits with ease and that's with a RTT, bed full of gear, and 34" M/T tires.

 

[Rviator]

Not entirely true - the turbo has a single function - to supply boost when it's needed, as far as air/fuel ratio the engine management system works pretty much like a na - fuel injected engine with sensors , calculations and feedback (lambda) loop to maintain the correct a/f ratio.
At altitude the turbo will have to spin faster to compensate for the less dense air - this spinning takes a small amount of power from the engine (compared to sea level) but it's extremely small but does increase linearly with altitude increase. Back in the day of carbureted engines it was a different story - in most cases there was no ability to adapt the af mixture at increased altitudes and the engines ran rich to the point that some would foul plugs and stall out, sometimes folks would lean out the mixture when headed to the mountains.

The turbo makes up for the less dense air at altitude irregardless of electronic engine management. A turbo charged engine that utilizes a carburetor will operate exactly the same way with no appreciable decrease in power at altitude and no change in air/fuel ratio. The turbo is powered by engine exhaust so it does add some exhaust back pressure. For a given engine power output it will take little if any additional power to spin the turbo at altitude then at sea level, It just spins faster at altitude due to the higher volume of air being consumed by the engine.

 

[dtech]

Turbo charged carbureted suffered from the same inability to correct the af mixture at higher elevations as na engines, air at 10k ft is less dense and there is less oxygen available so the mixture needs to be leaner - which most carbureters cannot do ( I had a 1980 Honda with a altitude mixture adjustment) So you can force more air into the engine but if you can't control the AF mixture the engine will not run efficiently. . Saab is widely acknowledged for making turbo charged engines practical from a everyday driveability standpoint as they were the 1st to utilize solid state engine mgmt to control boost , they called it automatic performance control (APC) and it used electronic fuel injection, a lot of earlier attempts to turbo charge carbureted engines were short lived owing to driveabilty issues.
Again the engine management system determines the proper AF ratio whereas the turbos function is to supply boost when needed and it does not determine the AF ratio as you previously stated.

 

[Rviator]

Turbo charged carbureted suffered from the same inability to correct the af mixture at higher elevations as na engines, air at 10k ft is less dense and there is less oxygen available so the mixture needs to be leaner - which most carbureters cannot do ( I had a 1980 Honda with a altitude mixture adjustment) So you can force more air into the engine but if you can't control the AF mixture the engine will not run efficiently. . Saab is widely acknowledged for making turbo charged engines practical from a everyday driveability standpoint as they were the 1st to utilize solid state engine mgmt to control boost , they called it automatic performance control (APC) and it used electronic fuel injection, a lot of earlier attempts to turbo charge carbureted engines were short lived owing to driveabilty issues.
Again the engine management system determines the proper AF ratio whereas the turbos function is to supply boost when needed and it does not determine the AF ratio as you previously stated.

You are incorrect on so many statements here I'll just exit the discussion at this point. I'll only say learn about turbocharging and why it was invented for use on, yes carburated, piston engined aircraft.

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