cruise control = better mpg?

[robmac]

Just a question really does usign cruise control offer better or worse MPG. I've got a 1.9tdi 105bhp sportback and travel 15 miles each way to work on a dual carriageway.

Been using cruise a little bit and the revs seem more "managed" but just wondering if it would have a better or worse effect on mpg?

[Sloggs]

Ive noticed it's good if your not driving in a hilly route, when going downhill it uses the engine to brake, to maintain the speed, if you take cruise control off when going downhill you can see the MPG figure shoot up.

[Scapegoat]

Depends on the route. If you have a route with hills, especially long ones, then a fuel efficient way of driving is to let the speed drop a little up the hill and then gain some back down hill.

If you set the cruise at 75mph, the car will put as much fuel as necessay to ensure 75 is maintained all the way up a long hill. And that can be a lot!