I am not seeing that the cruise control in my TCH is working as it should...or as it works in my non-hybrid gas guzzling Chrysler. With the Chrysler, I set the cruise at a given speed and it stays there no matter what the terrain...uphill or down...no matter how steep.

With the TCH, though, it will only maintain my set speed on level ground or going uphill. Going down is a totally different story...tonight I set the cruise for 35 mph and finally put the brakes on because of a corner but I was up to almost 50 mph! Is this 'typical' with the hybrid or Toyota? My old (1988) Honda didn't hold the cruise as well as the Chrysler but not this poorly.

Any other experiences? I know that the manual states 'changes in vehicle speed may occur on steeper grades'... Is this something to talk to my dealer about? Can it be adjusted? This is the ONLY complaint I have about my beauty!

 

I have noticed the same thing on downhill grades. The cruise control doesn't seem to be able to use engine braking so you just coast and continue to gain speed.

 

I guess I'm not surprised by the TCH cruise control behavior. I've had cruise on the last 7 vehicles I've owned, and rented over 100 cars in the last couple of years, and every one of them will speed up going down a steep enough hill. They all regulate the speed simply by adjusting the throttle. None also use the brakes as part of the cruise control system. Now, the TCH does coast a LITTLE freer than most other vehicles, but the difference is small.

 

My understanding is that the ICE is not connected to the transmission except when you have the transmission in "B", (This is engine braking).

One other thing, the transmission does not have gears, it has cones with a belt between them to drive the wheels, therefore it does not have much hold back power. In other words the car will act as though it is free wheeling on downhill grades.

 

I've noticed this as well, and not just on the TCH. It happens with older Toyota vehicles that I've driven extensively ('90 Camry, '99 4Runner). Like Barb's Chrysler, the cruise control on a Mercedes is quite accurate even on varied elevation changes. It's also smooth; sometimes I wouldn't notice that the car is accelerating or decelerating to match the set speed.

 

That statement about cones in the CVT is wrong. That is not how the TCH CVT works. It is an electronic CVT, not a mechanical one that uses belts and cones and uses the 2 motor generators to regulate speed.

 

I have never had a car with cruise control before, and since I don't drive standard I don't drive my husband's Jetta that does have cc. I think my cruise control works fine, but I only use it on relatively flat areas of the highway. My husband, on the other hand, says that his Jetta's cruise control keeps the car at EXACTLY the speed he sets it to, and he thinks the TCH cruise control is wonky because it varies up and down by 5mph.

 

Lil,

Our TCH cruise control maintains within about +/- 1 mph (unless a downhill slope is too steep). Maybe yours has a problem.

 

Yes, on downhill slopes the regenerative braking on coasting does not hold the car back as much as engine braking on a conventional car. Hence, it coasts a little freer. It's pretty far from a freewheeling coast that you'd get from any car in neutral, but it's freer than normal engine braking.

The worst cruise controls I've experienced (have rented many of them) are on Nissan Altimas and Maximas, where they overspeed by 3-4 mph as soon as you start going downhill, then back off to the set speed. This happens on every hill, even small ones. The TCH cruise control works much better than this, even without as much resistance from engine braking.

 

So what is determined to be 'too steep'? What % grade?

Also, how does everyone use the 'B' mode? There really doesn't seem to be much info in the manual about how to use it...