S Mode & ECT Use for Mountain Driving

In mountains I regularly pop from D down into 3 or 2. If I don’t feel that it’s slowing down as much as I want I keep going lower. If the engine is suddenly louder than I want, I’ll bump the gear back up.

 

You could not be further from the truth. BC is no longer the cool rainy province it used to be. Like much of North America, we are in severe drought through most of the province. Where I live, we see 95+F about 40 days during summer, and during heat dome we saw 110+F for a couple weeks. Since January 1st of this year, we have received a total of 2.5 inches of rain in 7 months. This year by July 1st we had already burned through more timber in wildfires than in any previous full wildfire season.

The routes I drive, I see a car or truck or 18 wheeler burned out on side of the highway on a weekly basis. Either overheating engines uphill, or downhill set on fire by burned brakes. A good reason why I carry 3 fire extinguishers in my truck and 10 gallons of water in the pickup bed plus axe, shovel, etc.

On my return highway trips downhill, it is not uncommon to see 18 wheelers that took a runaway lane up a mountainside after their brakes failed. Brakes that failed while they were going a maximum of 20mph down a 25 mile long hill.

This is just one example from one of those hills, this one closer to Hope BC. This guy set on fire going up that section.

I have a bunch if photos too of rigs and cars burned up on the hill from Pennask summit to West Kelowna. I never travel it uphill after 8am or downhill after 10am in summer as it is just not worth the risk.

 

Think of it as a manual transmission without the clutch. On flat ground at normal speeds I just put it in D and let the transmission do it's thing. But if I'm in an area where the top speed is going to be under 40-45 mph the transmission keeps wanting to go into higher gears than it really should. In those situations, I shift to 4, sometimes 3rd. The truck drives normally, it just won't go above 4th gear. (I have a 5 speed but the same principle applies to a 6 speed). This keeps engine rpm in the best range for those speeds. You have more power, better performance, a cooler engine, and better fuel mileage.

In mountains I'm shifting gears quite a lot even with my automatic. The automatic transmission only reacts to changing road conditions. It can't see the road ahead and anticipate which will be the best gear. It will only downshift AFTER the engine starts to struggle. I can see an incline and know the transmission will need to be in 3rd, or maybe even 2nd gear in order to get up. I will downshift while engine rpm's are still high and never lose momentum. This is easier on the engine and transmission.

Coming down mountains I put the truck in whatever gear will hold the speed limit with minimal braking. That could be 3rd, 2nd, and occasionally even 1st gear.

This doesn't mean you NEVER use the brakes. But you can greatly reduce how much you need to use them. It won't hurt a thing if done right. You can't be doing 40 mph and downshift to 2nd gear. But once you use the brakes to get to a speed where 2nd gear is appropriate then downshift. Its literally no different than a manual. You just don't have a clutch.

 

I wonder if the backup lights come on?
Might really get someones attention if they're tailgating you pretty hard.

 

Not to revive an old thread, but now that I’ve driven this thing some more, it appears to have some built in engine braking. I’ve noticed when going down steep hills in regular D that if I tap the brakes the RPMs shoot up and the truck slows. Yesterday going down a steep hill I hit the brakes for a second and the RPMs jumped to about 4K.

Is this normal operation or does that sound incorrect? I was concerned that was a little high. I don’t have ECT or anything on and mine didn’t come with downhill assist. If this is normal, it appears I’d have no real reason to use S Mode for my needs as it seems to automatically engine brake. But if it’s not normal - I would want to have the dealership look at it.

 

Yeah mine does that on one particular hill even if I’m just coasting it automatically shifts down to 3rd at around 55mph. I have to put it into S and shift up to 5th or 6th to override it. I feel like the truck thinks it’s picking up too much speed whilst coasting…?

4k revs is within the engine braking range.

 

And to confirm - in this example, it would downshift on its on to 3,2,1 depending on speed and if I come to a stop? Basically can just flip it into S4 when I start and drive around town as long as under 50mph and I don’t have to ever worry about shifting up or down?

 

been playing around with ECT mode again and it seems like it does much more than just raise the shift points. I feel like i have more power at the same RPM as not using ECT mode. Anyone know what actual parameters are being changed? feels like a different engine entirely.

 

Correct. Give it a try. I guarantee that fifteen minutes of hands-on goofing around will explain more than 20 pages of reading.

 

It's also going to slightly change a few of the engine parameters also. The engine really is an odd duck - with multiple injection methods and the ability to cycle between Otto and Atkinson timing on demand, it is more than capable of tweaking a few settings to squeeze some horses when it wants to. It's part of why it took the tuner crowd several years to figure it out. For a midsize truck with a run of the mill motor, it's got some amazingly complicated electrons playing under the hood.

 

I think the throttle response is a little livelier too.

 

You can probably get away with using it over 50 mph too but I'm not certain what the exact limit would be. But I think it should be over 50 mph.

 

You can keep it in S2 if you wanted under 50mph. Second gear can hit 60mph.