What do other members think about using cruise control in relation to fuel economy?

I have found this feature effects different cars in different ways when it comes to economy. For example, on my previous i6 FL2 it actually helped with economy to use the cruise control but on my old Volvo V50 diesel it adversely affected the old mpg.

Not had a lot of chance to assess it on my TD4 HSE auto yet but was hoping some of you may have some comments to make.

Cheers, Reg 2010 HSE TD4 auto, Biscay Blue, Almond Leather, facelift front and rear, detachable towbar, front & rear mudflaps, bib spoilers, clear high level brake light, smooth rear wiper, colour coded door handles.

Previous Land Rovers:
2007 Freelander 2 HSE i6 in Stornoway Grey
1991 Discovery 200tdi 3 door in blue

I use cruise when on motorways and dual carriageways where appropriate. It certainly comes into its own with an auto, where with the manual you have to relect after a gearchange is needed, of course. It is interesting to note that current HGV driver CPC teaching advocates use of cruise to aid fuel economy. 10MY (Sept 09) TD4 HSE Auto in Stornoway Grey (Now Gone)

08 FL2 TD4 SE Manual in Rimini Red (Now Gone)

My experience on a V70 D5 and a Cooper S showed that it helped by a couple of mpg in each case. I find it more helpful to avoid speeding as my FL2 seems to have a natural cruising speed of 90mph and I have to keep reining it back in! I must remember to use the cruise control more....

I haven't gone to the trouble of comparing mpg with or without cruise but my morning drive to work down the A38 usually means I don't use it. This is because of rush hour traffic and lorries pulling out to overtake lorries and taking 2 miles to get past

I sometimes use it in built up areas if the conditions are right. There is a main road running through the town with a couple of speed cameras and if the road is quiet enough I activate cruise at 30 in 4th and glide along past the gatso's. LL.B (Hons) - University of Derby
LOT (Lord of Time) - University of Gallifrey

I have tried it and the mpg is worse, coasting on a downhill stretch without cruise, foot off and the instant mpg goes to 99.9, with cruise on it will hover in the 70's mpg suggesting it is keeping the throttle slightly open?

All the cars I have had, very rarely used it

Ι believe that to a relatively dense traffic
rather annoys me.
In the motorway we've certainly economy.

Thanks for all the replies so far.....

I am off down to Southampton tomorrow so will give it a try and report back in a couple of weeks when I return...

Reg  2010 HSE TD4 auto, Biscay Blue, Almond Leather, facelift front and rear, detachable towbar, front & rear mudflaps, bib spoilers, clear high level brake light, smooth rear wiper, colour coded door handles.

Previous Land Rovers:
2007 Freelander 2 HSE i6 in Stornoway Grey
1991 Discovery 200tdi 3 door in blue

I rarely use it too, the only cruise control system thats any good is the adaptive type that slows you down to a safe distance when you approach something coming up in front then speeds you back up after youve pulled out to pass it, otherwise its continuous off and back on again, the standard system is only really useful on motorways around 2am in the morning when everyone else is in bed.

Don't rely solely on cruise control to keep you to the speed limit. Set it at 30 mph and go down a steep hill and speed can creep up. I've heard of some getting done for speeding in an RRS for just that reason.

Merc cruise control maintains speed even downhill, LR runs away with itself which is a shame.

Speed warning/limiter would be much more useful, I have read somewhere that speed warning systems will become a requirement on cars in the near future.

I use it on motorways when in roadworks with a 50 limit, tricky setting it right as there is always someone slower than me but it can be useful. Used it once on a fairly quiet M74/M6 at 80 and was happy.......... JT Upgraded to an ex demo, 7 mth old, Rimini Red/Ebony Napoli Auto HSE on 28th Jan 2011, added roof rails, mudflaps and side strips.
Gone - A great 57 Plate, Auto SE, Bought Feb 2009, Roof Rails and Mudflaps added on purchase. Blue colour, anything but drug dealer black.....

cruise was usefull during the recent long running and extensive 50 mph on the A1 road works, other than that its mainly annoying in UK traffic, you either end up tailgating someone, or you let a gap open which immediately fills with mondanos or bmw's like moths to a light bulb  At work
At home

"I can't always believe facts I read on the web" - Charles Dickens

winner by default of the tractor vs caravan race

I use it every day to and from work from Jct 6 on the M3 until A342 on the A303. I have an SD4 Auto, I cruise at 75-80 and achieve an average of 35mpg. With cruise on and going downhill the instant fuel read out is 99.9.

Hmmm...i will try mine again tomorrow, it was barely run in when i tried it, maybe it was a bit tight and having to overcome more friction than normal.
Will report back.......