Blogs Car Info Our Show Deals Mechanics Files Vehicle Donation

Struggling on the highway: Should I turn off Overdrive?

A little background on my truck: Its a 2003 Nissan Frontier SE Crew Cab with a 3.3L V6 2wd, RWD AUTO. 78,000 miles. (yeah, I live in CO, so having this truck here doesn’t really make sense when described through text, but with tire chains, and 200lbs in the bed it does better than most 4x4’s if you know how to drive rwd! ha.)

Anyways, I drove up to Aspen, CO and back from Colorado Springs (~575 miles roundtrip) for my rugby game and man did my truck have a hard time getting up the mountain passes.

The speed limit in some places was 75 mph but I struggled to make it to 65 with the pedal floored-i think the grades were about 7% so not that much really for CO. I also noticed that my truck had trouble shifting into the right gear in my opinion. I would be in 5th, and it felt like it would shift down to third and rev really high rather than shifting into 4th?

My shifter knob has a button to turn off Overdrive, but i just didnt remember to turn it off and try driving like that, but would turning off OD help me make it up these mountain passes? If i can find some way to drive my truck up to Aspen without all the hastle (and embarassment) of not being able to go the speed limit, I would be so happy-that way I wouldn’t have to drive our passat up there.


Mostly you should first make sure that you don’t have an issue with the truck - like old spark plugs & wires, dirty air filter, fuel filter. Check the fuel pressure. Check for exhaust restrictions.

If your transmission really had a problem I’d suspect a check engine light and some error codes. IF you don’t have that, you might have someone put it on a scanner anyway just to make sure.

Other than that, yes, turning the O/D off if a fine idea for climbing.

Is it common to replace sparkplugs and wires at 78,000 miles? It certainly would be a good idea to look in to as it did wonders for my trooper-(but that had 215,000 miles on it and they had never been changed before. Ha!)
Also, these hills are many miles long, and there are maybe 5 good hills that I struggled with, so are there adverse effects for leaving OD off for this long? And no, the check engine light is not on, and has never actually come on since ive owned it. And the air/fuel filters are both good.

I commend you on your winter preparation. I am hard pressed to feel why this truck with this excellent motor should lack performance in 2wd. I would check the transmission function and tune up specs as suggested. Though turning off the OD shouldn’t hurt, there is really no need to do it as it should functionally down shift for you.

Its not common to replace plugs & wires at any given mileage. Its wise to check the owner’s manual and find out what it says. I’ll guess that it says to change the plugs at any point between about 30K and 100K miles. It varies by vehicle/spark plug spec - so there is no “common” that applies to all vehicles.

But I’m more certain now that I’d do basic maintenance stuff before anything else. Going over 200K with same plugs (in that Trooper) is just neglect. Everyone’s free to neglect their cars if they like. They just shouldn’t wonder about crappy performance if they do. That doesn’t mean I’m saying your problem is with the spark plugs. But holy cow - it would take 5 minutes to check the maintenance schedule and another 5 to pull one out and look at it.

And don’t brush off the fuel pressure & exhaust checks.

You’re not going to hurt anything by leaving the O/D off while climbing hills.

I’m not sure if you were trying to criticize me or not-its tough to decipher sarcasm through writing-but yes it was neglect in the case of the trooper. I bought my '94 trooper last summer with 214,000 miles on it as a project to try and learn a little more about cars. I got it for $200 off craigslist with a blown head gasket, brakes ground down past the pads to where the cylinder was on the rotor, blown rear axle seal, leaking speedo seal, power steering leak, all four shocks shot, several small things like spark plugs/wires/tube seals, new window actuators, replaced broken door handles, broken windshield and it most likely had never been cleaned (inside or out), but I fixed it all (on my own with the help of a chilton’s manual) over the summer and learned a bunch! And after all that, it drove like a new car. I put maybe $900 into it and sold it two months ago for $2800-not too shabby!
As for my Frontier, I take it to my local mechanic to have the work done as he is more qualified to do the work (on a car i actually care about).
But i will certainly ask my mechanic about fuel pressure and exhaust checks.

*as for my crappy performance, maybe a 3.3L V6 just isn’t a large/powerful enough motor to pull a truck and three men and a bed full of gear up mountain passes at an elevation of 8500 feet?

Taking the 200 pounds of sand out will help quite a bit…But yes, by all means, lock out the overdrive to prevent all that needless shifting (and wear) when pulling a steep grade…That’s why they put that button on there…

People lived and drove in Colorado long before 4WD/AWD vehicles became common. The roads were a lot more difficult too. They did just fine…And no weekend traffic gridlock then…

ha the sand was not in the bed yesterday-i figured my buddies could sit in the bed if i got stuck so i took it out before i left! good thing too. ha. but i never leave the house without my chains-plus its a $500 fine if you try to drive up I-70 in the winter some days in a 2wd car/truck without chains on! Welcome to CO!

I wonder if your problem in struggling to maintain speed might be caused by a partially plugged exhaust system. A friend of mine had a similar problem driving in the mountains in Pennsylvania on a trip. Things got so bad he had to take it in for repair before he could make the return trip back home. It turned out that his catalytic converter had disintegrated on the inside and was partially plugged.

I wasn’t trying to criticize you. I was just giving my assessment. Hang around here for a while. The world is full of people who completely ignore their cars for very long periods of time. When they start to have problems they show up here - and then someone has to explain to them that there is a maintenance schedule for the car and that the maintenance schedule items really aren’t some kind of a scam. I don’t know whether or not that applies to you. But if it didn’t you wouldn’t say “Is it common to replace sparkplugs and wires at 78,000 miles?” You would say “but I’m not due for plugs until…” Then there’s your other post about the timing belt. Check the maintenance schedule.

So here’s the general point and take it as advice rather than criticism: anytime that you have any question about a vehicle & its performance or whatever don’t do anything else until you make sure that all basic maintenance is on order.

  • One other thing people do is start giving out more info as the answers move in an unanticipated direction. One minute its you + 200 lbs. of stuff in the bed going up a mountain. Now its you with 2 other people and a bed full of gear.

200 lbs is nothing for weight and should affect your performance very little and you’re fine with it, even if it were just a 4 cyl. With a 6 and 2wd, you should ALWAYS travel with substantial weight in the back of greater than 200 lbs in the winter to help- offset the added 6’s weight. You will notice very little difference removing 200 lbs in a truck that was meant to carry well over 1K with ease. The over drive is an option only on your part for going up hills. The auto should know when to shift if it’s working OK. I’m in agreement that something else is amiss. I had a similar model, Toyota 2wd with a 3.0 6 cyl(smaller than yours and IMO the Nissan 6 is more powerful than mine), and mine had all the power I needed for normal driving for hills and recommended towing.

Well, lets see…

You had 3 men, a bed full of gear for your rugby adventure (what equipment do you need for rugby?).
We don’t really know the maintenance history of the vehicle, nor how long you have owned it, and what all you have done to it in that time period.

If it was my truck, here’s what I would do:

Buy new spark plugs if its a coil on plug system, or add in wires and a cap and rotor if it has those. New fuel filter, new air filter, oil and filter change, plus a bottle of Chevron with Techron Fuel System cleaner, or two, it its a large tank capacity (only 20 gallons, so 1 and a half bottles).

I would also change the transmission and rear differential fluid, so I wouldn’t have to wonder about those anymore.

Then, when driving in the mountains, I would progress from being in Drive with overdrive active, to Drive without Overdrive, to 3rd Gear, to 2nd gear, as needed for the various inclines and declines. All shifted manually, by me, and not letting the transmission hunt and peck for what it thinks is the right gear.

But that bottle of Chevron Fuel System Cleaner would be the top of my list.
Get the fuel system cleaned out the best that I can, and then work around everything else to bring the truck back up to snuff.

As for your question about if the motor is big enough for the mountains, it is.
It just doesn’t make enough horsepower, since it seems to be the 180 hp version.
You lose roughly 4% of your hp for every 1k foot increase in elevation. At 5000 feet, you are already down 20% when you started your trip, which means your 180 hp engine is only making 144 hp. At 10k feet, your engine only makes 108 hp.

Now, if you had the 210 hp Supercharged version, you wouldn’t lose nearly as much hp, as the supercharger would (for the most part) keep the engine under sea level conditions for the entire time it is under load.

So honestly, there most likely isn’t anything wrong with your truck.
Just learn how to shift the transmission manually.