Grrrrr! Cruise control....MPG wrecker

[Gogogordy]

Just finished a 3800 mile RT San Diego CA to St Robert Mo and back.

Hate todays digital cruise control....no longer a set-it, forget-it proposition....at least if fuel economy is on your agenda as well as comfort.

The problem with today's "digitally" controlled cruise control is this:

Unless youre travelling on perfect flat roadways without any overpasses, or undulations for terrain, the cruise control forces the AT into passing gear at the slightest hint of incline, in order to stay at the set speed without any variance.

The passing gear surge essentially shoots your MPG squarely in the keister, and not in a small way.

During the trip I eventually got to the point where I'd disentage the CC in advnace of any slight incline and manually control the throttle to keep the engine RPMs constant even if my speed did drop 1or 2 MPH while ramping up.

Thats all fine, but in practice it becomes more work than driving without using CC. In past years (well for us OLDER folks anyway!) the cruise control provided both a quiet, and "nearly" constant speed ride, while delivering the best possible fuel economy possible. Neither of those former benefits apply in todays digital, drive-by-wire vehicles.

The digital nature of these things makes the cruise control strive for an all-or-nothing operation, without any of the finesse possible by human (analog) or old-school (also analog) cruise control systems. Thats the shortcoming and thats why modern cruise control technology is more a marketing point anymore, than a viable feature for anything but mindless, and fuel-thirstier driving. A shame.

If anyone, including the Hypermilers reading this have any further suggestions or workarounds for this, I'd love to hear them. Otherwise, I'll consider cruise control a semi useless option on an otherwise great vehicle.

[NEexpat]

During the trip I eventually got to the point where I'd disentage the CC in advnace of any slight incline and manually control the throttle to keep the engine RPMs constant even if my speed did drop 1or 2 MPH while ramping up.

^ I use my CC ALWAYS, and on a recent trip through PA. on my way to OH. I experienced exactly what your talking about. Going up and through the Alleghenys the CC would drop the gear and RPMs would scream.

I did exactly what you did, disengage the CC mantain speed, and reengage after incline. I am hardly a hypermiler but I do try to squeeze out every mile I can, and I don't know of any work around other than what you and I are already doing.

[matti]

I had a 2005 Corolla with AT and that problem drove me completely crazy. All of my cars since have had MT, and the problem isn't as pronounced. Good luck.

[Altitude]

Not a problem with manual transmission :wink:

[Gogogordy]

Not a problem with manual transmission :wink:

Based on my experience with my former 6 speed Mini S, the problem is exhibited a bit differently in that your forced to downshift and re-establish the CC anyway.

As the poster above above said, it's not as BIG a PITA with a manual, but that doesnt change anything for those of us driving slushboxes...

[caineroad]

i know the problem you are talking about, i dont get inclines here at all, so i dont experience as much. But this Toyota CC is by far the best one I have used, it maintains the speed very well (despite the RPM surge). When I set it to 60, it crusises at 60. But other CC when you are going uphill/downhill, speed can lower to -5/+5 or more so i still prefer toyota's CC.

[edmscan]

I personally do not use the cruise control in my Yaris. I have just found that it does its job as advertised (yes it does keep the car going at a constant speed), but I have determined with my ScanGauge that I can do a better job when it comes to fuel economy.

For some reason ... it just uses more gas when it is on cruise control. Besides .. I don't like the loss of control when using the cruise. I prefer to have control of my car ... so the cruise never gets used anymore.

[Idahotom]

I always wonder, when I'm cruising down the interstate at 60 mph with the CC engaged, and I notice a car quickly gaining coming up behind me, and rather then pass they park it on my ass for a few minutes. When it finally penetrates that yes indeed I am going slower then they want to go, they pass and accelerate back up to 75 or so and quickly leave me in their dust.

Or, when I am passing someone (rare), with CC engaged, at a consistant rate in other words, and they speed up so we pace each other, making the passing manuver take longer then if they had just maintianed their frigging speed.

My aftermarket cruise is great, and I use it a lot. Sure on hilly terrain I can do better by hand (so to speak), but I am amazed how, judging by their driving, how many people obviously don't use it. I feel it frees my attention up just a tad also, I never look at the speedo but out the window, at the traffic. 5sp. BTW

[caineroad]

I use it cuz it keeps my leg off the pedal, I am lazy :p. I even use it on city roads.