Cruise control and fuel economy

That's me I'm afraid...the old "are we ever going to get there" right foot comes into play too often.

Yes Iamaway , you have to practical.

The main issue with cruise is over acceleration up a hill , and car doesn't know its going up and just juices it. Then over the top your going to fast , which can be a bit hair raising at times in my ca which has a lot of power.

I find best is to leave on cruise on relatively flat terrain and as going up a big hill I just cancel and press resume over the top.

If I feel car will do it , instead of cancel I just kick it into neutral and roll the hill.

Robin Miller

Thats why Mercedes, BMW etc noe connect the brakes into the cruise control.
If engine braking is not enough , the puter puts on the brakes.
I think they need a smarter puter in the first place!

doesnt rolling in neutral stuff the trannie? (probablly not in that distance but with a 3 grand plus box I wouldnt be trying to save .5c of fuel)

Assuming of course you are talking of an auto

No Dave I'm talking about a manual ,is not worth it in an auto.

Some auto's like a RAV4 I drive can not easiy be flicked into neutral without conncentration anyway, whereas it can be done automatically in a manual (I had to get that in).

But it would not stuff an auto -( we are talking occasionally for 2-3 hundred meters a time).

Robin Miller

well done

Hi there Philip, I disagree with that theory, if the fuel was cut to the injectors the vehicle would stall. My commodore which I just sold even going down hill in overdrive would still be showing at least 1500 rpm going down hawksbury on the f3 the new toyota I just bought for my wife 06 model revs even higher with foot off the throttle going down the same hill. I would imagine this would be the case in any vehicle that if you take your foot off the throttle and the fuel wasnt delivered to the engine it would stall. And as far as putting in neutral whilst cruise control is in actve state in auto will cause the engine to rev its nut out as there has been nothing sent to the computer that you have touched the brake or cancelled out the cruise control so putting in neutral especially when going uphill will cause once again for the motor to rev up as it is wanting the power to maintain the speed but with it in neutral is unobtainable then the only way to stop it revving its guts out is to cancel either by foot brake, clutch pedal if manual or turn the main cruise off. Putting any vehicle in neutral and coasting along unless about to pull up at lights which I do (cheaper to replace pads than a clutch) to me is totally dangerous as you have no control over the vehicle in an emergeny situation. Steve M

...I had no control reading that reply - hardly a punctuation used.