Leaving high altitude to sea level

I have an 89 dodge ramcharger 4x4 with throttle bodied 5.9 360. I live in Utah and moving back to Ohio. Do I need to worry about any adjustments when leaving the high altitude?

I wouldn’t think so. I moved from the high desert of Arizona several years ago and both of my vehicles ran great in the lower altitudes. If you used 85 octane in Utah…you probably won’t even notice a change when you start using 87 octane.

Sweet thanks man just first time driving anything that far and wanted to make sure

You might expect a drop in gas mileage at high speeds. The denser air will make more air resistance.

The computer will take care of that.

Only the old non-computerized and carburated trucks would be at issue.
We think the 89 should be new enough but watch your temp gauge to be sure. If the computer does not compensate and adjustments are needed, you’ll see it running hot. ( due to running lean like my Cessna which had an air/fuel adjustment knob and an exhaust manifold temp gauge )

My 80 Bronco did just that…even just going form Gallup’s 6500 ft to Albuquerque’s 5000 for the day, it would rum hot but not over heat.
A trip to see family in Ohio would require carb adjustment along the way.

In the olden days we would manually advance the timing for higher elevations, I also think this is something you will not need to worry about.

His 2 cents is wrong. What the computer can adjust for is the correct air-fuel mixture, which cars of olde could not do. However, the air resistance effect of denser air is real physical work that the car must do, pushing the air out of the way. The air is heavier at lower altitude. There is no way to compensate for this by engine adjustments.

The OPs question was what adjustments he should make. What adjustments would you make? The vehicle in question DOES have a computer complete with O2 sensors among other sensors. I stand by my post.

Pushing air out of the way would apply to any vehicle regardless of the level of computerization.

@melott OK, I see why you thought I was wrong. I was responding to the OPs question, not your post. Obviously the computer can’t compensate for wind resistance. I can see why there was confusion.

Driving a long way the first time does sort of seem like a polar expedition.

In December 1964, I put a rebuilt motor and transmission in my 1953 Chevrolet. I left home at noon one day, and 50 hours later was 2050 miles away in Fort Lewis. This was when only parts of I-80 were done.

I felt I was on a round the world expedition. I will never forget that first long trip.

Now, since I retired in 1997, I have driven somewhere around 300,000 miles, most of it on long trips. in 2005 I left my house in Mexico, and returned 59 days later, after having driven 11,000 miles. I hated my car for a while…

I have never fallen asleep while driving, which is really strange because I often fall asleep in front of my computer. I drink caffeine and chew gum to stay awake while driving.

On your first long trip, check your oil every time you add gas. And, do not go below maybe 1/3 tank of gas before filling up again, just in case there is a power outage in some location.

Before you leave, check your hoses; belts; and tires. Also every day check your other liquids.

I agree that back in the days of Carburetors…before fuel injection and computerized engine control it was an issue. But now days with the advanced systems in almost everything built after 1990 there would be little concern unless there were other problems already with the fuel injection or engine control at lower altitudes.


One potential issue could be if someone in the past had advanced the ignition timing to compensate for higher altitudes.
This vehicle still uses a vacuum advance I believe and going to lower altitudes could affect the timing and cause it to have more advance.

One thing not needed is too much advance as that can be an engine killer. Maybe it would be a good idea to have the timing checked and verify that it’s on a factory setting.

Even some carbureted engines were computer controlled. I had a 1984 Buick Skylark that had a throttle position sensor built right into the carburetor which had a little push rod poking through the top of the carburetor which was operated with a little piece of linkage. The signal this sent to the ECM operated a mixture control solenoid inside the carb. This replaced the power valve that was used in older carbs.

I think all carburetors from 1981 and up are controlled by computer although some pickups and off-road vehicles may have been an exception.
There were some cars that offered different carburetion based on where the destination was for the car shipments with a high altitude version assigned to dealers in the Rockies and so on.