Need help with driving thru Mountains...Automatic

[96ToyoCam164K]

Ok, I added like an hour to my trip this afternoon because I could not figure out how to do the gears going up and downhill while driving thru I-70 in Colorado thru the Rockies.

I was literally stuck at like 45-50 mph on the inclines, while everyone else zoomed by. They were continuously elevated for several miles. Switching into the recommended 2 gear didn't seem to help as the car would rev to 4000. By the way, at 3000 RPM...that would be equal to going about 80-90 mph on flat land. Yet, I was revving 3000-3200 at only 50 mph! I was terrified I would overheat my transmission.

Going downhill, shifting to L seems to make it go slower, but still keeping the engine revved at about 4000.

Is it okay to switch gears while driving? Which gears should I use for uphill/downhill and do I turn off Overdrive when doing so? Have another big drive tomorrow and dont want to overwork the tranny!

[theycmerollin]

Leave it in "D" with overdrive off.

If you're climbing, you want revs and lower gears.

O/D is a highway, economy gear.

[b2p1986]

Originally Posted by 96ToyoCam164K

Ok, I added like an hour to my trip this afternoon because I could not figure out how to do the gears going up and downhill while driving thru I-70 in Colorado thru the Rockies.

I was literally stuck at like 45-50 mph on the inclines, while everyone else zoomed by. They were continuously elevated for several miles. Switching into the recommended 2 gear didn't seem to help as the car would rev to 4000. By the way, at 3000 RPM...that would be equal to going about 80-90 mph on flat land. Yet, I was revving 3000-3200 at only 50 mph! I was terrified I would overheat my transmission.

Going downhill, shifting to L seems to make it go slower, but still keeping the engine revved at about 4000.

Is it okay to switch gears while driving? Which gears should I use for uphill/downhill and do I turn off Overdrive when doing so? Have another big drive tomorrow and dont want to overwork the tranny!

Based on what you said, I'd say get a 5 speed manual car

[96ToyoCam164K]

unfortunently i cant just go hopping into a manual when I've been driving ATF since the beginnning of time LOL.

So, keep in drive...O/D off? Whats the purpose of the L and 2? I get scared even switching to them as the tranny jerks and the RPM goes crazy to 4 or 5000.

I also used the power button, but of course all that does is make it rev to 5000...I really dont like the idea of revving beyond 4000...and cruise control loves to jump at every little incline (I've got a ton of stuff in the trunk, but I removed the A/C compressor and awaiting a replacement LOL)

[RningOnFumes]

There's a few misconceptions here.

Try this thread:

Fully-Automatic shift

Searching will get you a few more very helpful threads concerning this question of yours. Definitely also look up the term engine braking.

To answer a few of your questions...

L is basically 1st gear, 2 is second, D with O/D off is 3rd, and D with O/D on is 4th gear. Power button only allows the engine to reeve extra rpms before it shifts up. You should have no concern with high reves as long as none reach the red numbers.

Your manual should list the appropriate numbers for RPM in relation to the gear you were in. Going through the rockies or any mountain short of very drastic inclines, you should not have needed L. It was okay to have those high reeves in RPM because your engine was performing the act of engine braking-- very essential for long distance mountain driving.

Cruise control should not be on at all for anything but flat roads.



One last thing, engine RPM in the mountains does not equate equally to engine RPM on the flats.

(check out online vids concerning engine braking and hill climbs-- lots of info out there).

[bigbird]

you were also at a higher altitude = less oxygen, this may have had an effect. your engine needed a higher rpm even on flat parts to produce the same power.

[zythr]

Doesn't Toyota test the mountain driving ability of their vehicles at Mt Fuji in Japan?
?

[bigbird]

well any way your look at it it is less O2. toyota ECUs learn to adjust for that but not fast enough to have and effect on one trip, and likely not enough to really correct the problem that much. it would basically lean out the fuel but still require higher RPMs to perform.

[TedL]

Originally Posted by RningOnFumes

Cruise control should not be on at all for anything but flat roads.

Where'd that rule come from?

[Safari Wagon]

The toughest incline I have encountered towing my boat so far (only two months of towing) is the Conejo grade in Ventura County. It is known as one of the steepest freeway stretches in California. At 2.8 miles long and 7% grade, it’s pretty tough.

Going up this stretch, I have to downshift into second gear and drive about 50 mph. It feels like it will accelerate more, but I don’t want to push it too much.
(My boat / trailer combo has an estimated weight of 1700 lbs)

Do you have a four or six cylinder?

[Safari Wagon]

Originally Posted by TedL

Where'd that rule come from?

I tend to agree with keeping the cruise control off on uphills. The car wants to stay at a certain speed and will do anything to do so.
I've had the car downshift to second and rev to almost 5k. I don't like that too much...

I'd rather slow down a bit and not take the harsh downshift. It will also downshift right before the top of the hill - which I wouldn't do if I had control.

[RningOnFumes]

TedL, SariWagon elaborated on the cruise control. I remember reading that the manuals says that once you do hills, you should have the cruise off. Cruise keeps you at a particular speed, a hill forces the car to slow thus making the cruise compensate. The cruise control on our basic cars does not have any sort of fuzzy logic it just knows to maintain a set speed.

Your manual should list the appropriate numbers for RPM in relation to the gear you were in. Going through the rockies or any mountain short of very drastic inclines, you should not have needed L. It was okay to have those high reeves in RPM because your engine was performing the act of engine braking-- very essential for long distance mountain driving.

I noticed something faulty in my text. Addressing the engine braking-- it's for the downhills-- keeps the speed where you can handle the car appropriately and doesn't burn out/overheat the brakes. When you're ascending (climbing), you need the lower gears for the better torque/ power application- And bigbird covered that.

Zyther, I would imagine the testers on the mountain knew how to use their gears appropriately.

[deadrx7conv]

Altitude driving is stressful in an underpowered vehicle.

On downhill grades, if you're picking up speed and don't want to, disabled the OD 1st, and manual downshift as needed. You're are simply trying to prevent the brakes from tossing in the towel by using a little engine compression braking.

When going uphill, floor it. Step on the gas pedal. You don't have to bother with the shifter at all. Its an AUTOMATIC. But, to reduce numerous unneeded up/down shifting, you could help it along by keeping it in a lower gear.

The only way to protect the transmission is to monitor the temperature and to use a large enough ATF cooler to keep the temp acceptable.

The engine's red line is higher than 4000rpm. So, cruising at 4k-5k as needed is NOT an issue as long as engine temp is watched. Don't let it overheat. Just be aware that oil consumption will increase sometimes with this aggressive driving. Keep an eye on ALL fluid levels.

You're stuck in the slow lane because the engine is a dog and you're afraid of a little RPM.

[fenixus]

i'm not sure, all i did when climbing a very steep mountain road to the tip of Minnewaska State Park in NY, was keeping tranny with O/D off and at some point I decided to turn the ac off (middle of summer) for better response. it was s so with ac on and actually good with ac off. i was driving there with 5s-fe automatic.

[JohnGD]

When climbing for longer periods use D (and maybe with OD off).

L and 2 are for downhill because an extra brake band engages in those gears. Your transmission is more likely to overheat if climbing with L and 2.