Do i get better gas mileage with cruise on or off?
Experiment and find out for yourself. Driving styles, road conditions and terrain have a great deal of influence on fuel mileage. In hilly terrain I would guess that the cruise will result in worse mileage for those who are attentive to taking advantage of the descents relative to the subsequent ascents. But that’s just my gut feeling on it.
Traffic conditions permitting, you can better your cruise’s mpg by playng the momentum of the hills.
On the downslope give merely a toe’s pressure to the gas and allow gravity to speed you up. ( Or none at all and allow only gravity to speed you up )
Then keep the speed with momentum as you ascend the next hill, slowing only as gravity pulls you back, with only enough accelerator ( or none added ) to be at a reasonable speed as you crest.
Rinse and repeat.
The cruise will try drasticly to maintain speed letting waay off the gas on the down-hill and applying lots of accelerator on the upside.
I think that cruise control might give you a little better mileage, but as Rod said, the only way to know for sure is to test it out.
It depends on your habits as a driver. If you are smooth on the gas and maintain steady speeds it won’t make much difference. If you are on the gas and off the gas and your speeds vary accordingly then using cruise will save some gas.
Good on highway but tap it off going up hills and do not use in the rain
Conventional wisdom is that you get better fuel economy using the cruise control, but there might be some exceptions, like in the mountains where you can decelerate going uphill and accelerate going downhill to save fuel, or when you are hauling or towing a heavy load. In normal driving with a normal car, I use cruise control whenever I can, but when towing a heavy load, I often turn off the cruise control while going over hills to keep the automatic transmission from downshifting.
Mr. Green has it right in my view. We used to own a motorhome and I tried it both ways; with and w/o cruise. The gasoline demands of a motorhome quickly gets your attention for matters such as this. Cruise insists on maintaining uphill speed at whatever the cost; with whatever throttle opening it takes. If you let your uphill speed slow over the course of a particular hill, then that will save gas. If you don’t use cruise and then try to maintain a steady speed while climbing a hill, then you might as well use the cruise. You are smarter than the cruise control and can use that to your advantage. In flat terrain it will make little difference in fuel mileage if you use cruise or not.
It should be possible for a cruise control to do what you can do with your foot in hill country but vehicle designers are not yet there because the EPA mileage rating determination method is not yet there.
“You are smarter than the cruise control …”
The fact that the OP asked the question means that this statement is probably correct. But think about the recent thread where the guy asked how to keep his wife from destroying the car by driving it too harshly. That woman was probably not smarter than the cruise control, but she was also unlikely to accept advice to use CC to save fuel.
A conundrum – like with the law here in MD: if wipers are on, turn headlights on. The drivers who don’t have enough sense to do it just for safety also don’t have enough sense to know/obey the law.
Oops – I’m hijacking the thread.
It depends on your driving habits. Some people will get better with and some better without.