Dv6 Mk2.5 Focus - Optimum Mpg Speed?

[TomsFocus]

Hi guys,

Just wondered if anyone knew the optimum speed for MPG in the 1.6 TDCi Focus?

Done a fairly long trip today at a constant 70mph on cruise control but only got ~57mpg... I get a better average doing mostly town and B roads lol. Was hoping it would be at least 60mpg on a distance trip really. No mechanical issues afaik and I know about eco driving tips.

Cheers

Tom

[artscot79]

There isn't one since the mpg relies on so many factors like external air temp engine warm up time electrical load air speed the type of road surface if its flat or not etc since you use less throttle to maintain speed on a flat road but no roads flat you have up gradients and down so you can only read the road and do the best you can you're mpg is pretty good so I wouldn't complain none of the cars will do near the claimed mpg......if you saw top gear they drove the new BMW i8 that in a lab can do 155mpg yet in the real world it did 31mpg

[Dee_82]

Smaller b roads you'll be doing more lift and coast where as motorway traffic is sustained, those numbers are really good for motorway, I find on the dial about half way between 60 and 65 is best, which is in reality about 58/59

[jbeer]

I find that when I use Cruise a Control my mpg is not as good and this all down to the car constantly applying power & braking where as normal you can easy off the throttle and coast

[TomsFocus]

Aurthur, I see your point but there will still be a 'roughly' optimum speed - assuming the road was perfectly flat. Yeah I did see the i8...1.5 petrol hybrid and only managed 30mpg...don't even know how they managed that tbh. I also own a '99 2.0 16v GTi-6 that does near 30mpg!

Darren, I mean 70 on the sat nav, ~75 on the speedo. Such a shame they didn't stick a 6 speed 'box in the DV6 Focus. :(

Jason, it doesn't brake for you, only affects the throttle and effectively engine brakes/coasts when letting off, I know it'll use a little more on cruise uphill as it cant anticipate them but I end up creeping without so it does work better overall. I've gained a couple of MPG average over a tank since adding the cruise control and use it for ~75% of the time now lol. Just annoying that my average is always just below 60mpg over a ~600 mile tank and really thought motorway trips would be more efficient than my usual.

[jbeer]

Jason, it doesn't brake for you, only affects the throttle and effectively engine brakes/coasts when letting off, I know it'll use a little more on cruise uphill as it cant anticipate them but I end up creeping without so it does work better overall. I've gained a couple of MPG average over a tank since adding the cruise control and use it for ~75% of the time now lol. Just annoying that my average is always just below 60mpg over a ~600 mile tank and really thought motorway trips would be more efficient than my usual.

Maybe braking was the wrong terminology as when you go down hill CC does not coast as you could go over your set speed therefore the brakes/abs control your decent down a hill/incline? No

[TomsFocus]

Nope, they don't on the Focus 2.5! If you roll down hill on cruise you will go over the limit, think the book even says this and to drop a gear and hit resume on hill descents.

Some cars do apply the brakes as you say, but not these. :)

[jbeer]

Nope, they don't on the Focus 2.5! If you roll down hill on cruise you will go over the limit, think the book even says this and to drop a gear and hit resume on hill descents.

Some cars do apply the brakes as you say, but not these. :)

Nope not on mine, always stays at the speed set uphill or downhill

[TomsFocus]

Hmm, interesting, I know yours is a couple of years newer but I didn't know they had changed it?

[jbeer]

Yep definitely interesting, mines 1 year younger and different engine size not that I suppose that matters too much

[blue flash]

Yep,mines the same,same speed uphill or down..

[artscot79]

I can only speak from personal experience I have a road I drive daily nice long and flat if I was doing 50mph then my mpg improves slightly however if I do 70 it goes up a lot more because I can lift off and allow the momentum to keep the car going using very little throttle IDE say trial and error .....for me 65-70 works best

[Dee_82]

aren't you missing your 60mpg by only a fraction? slap 200mls of 2 stroke mineral oil in to the fuel tank, youll get your 60 and a bunch of other good stuff !

[south_bound]

A long straight flat A road on cruise control at about 60mph works well for me. There is one near where I fill up sometimes and I reset the mpg counter - after about 8 miles of this road the reading is often at over 75mpg, but then it drops as I get into hills, round abouts and town driving. As soon as you get into gradients I find its best to anticipate so you speed up as you go downhill, and slow as you climb which is someting the cruise control won't do.

[TomsFocus]

Yep definitely interesting, mines 1 year younger and different engine size not that I suppose that matters too much

Lol, I clearly can't count, yes only 1 year between them! No idea then lol, but mine definitely doesn't brake so I'm not losing mpg there. :)

I can only speak from personal experience I have a road I drive daily nice long and flat if I was doing 50mph then my mpg improves slightly however if I do 70 it goes up a lot more because I can lift off and allow the momentum to keep the car going using very little throttle IDE say trial and error .....for me 65-70 works best

Doing another lengthy trip tomororow so I'll try 65 and see if theres any improvement.

aren't you missing your 60mpg by only a fraction? slap 200mls of 2 stroke mineral oil in to the fuel tank, youll get your 60 and a bunch of other good stuff !

Yeah its literally 1 or 2 under every time! Not sure 2 stroke oil is good for newer diesels is it? I'd be worried about it causing damage?

A long straight flat A road on cruise control at about 60mph works well for me. There is one near where I fill up sometimes and I reset the mpg counter - after about 8 miles of this road the reading is often at over 75mpg, but then it drops as I get into hills, round abouts and town driving. As soon as you get into gradients I find its best to anticipate so you speed up as you go downhill, and slow as you climb which is someting the cruise control won't do.

Lol, I got 80mpg coming back from the fuel station on B roads at 40mph for 12 miles once...think I'd struggle to average it though. :D

I know cruise will be a little worse uphill but as said without it I tend to creep to 80+ which is obviously worse for mpg (and illegal of course lol). Will try 65 on cruise tomorrow, and 60 on cruise on Monday. Not sure I'll see any difference but will have to see!

[Dee_82]

ive been doing quite a bit of research on it and its fine to use, and is in fact recommended by a lot of folk, its all in the ratio, there is some debate around the whole DPF situation though, some say there is a small increase in ash generated, others say it increases heat burning more crap, I don't have that problem but its probably worth checking out some more for your new shiny DPF, driving back from stirling today via Livingston an I averaged along the motorway 78mpg! that's from heated so isn't a true average but the same trip used to give me about 60 odd. its the starts and traffic that cripples mine, been about 51 most of winter, creeping up to about 57 so far since I added the oil

[TomsFocus]

Hmm, yeah theres enough Eolys in the fuel to add ash to the DPF, probably best not to add anymore lol.

Tried 65mph on cruise today...exactly the same... Hit traffic so came back via the B roads with lots of accelerating, braking, hills, speed, etc and the MPG rose! I think the problem here is the gearbox.

The other diesels I've had have been 6 speed (except the 306) and 70 in 6th was under 2k rpm. 70 in 5th in the Focus is 2250rpm...so ~50 on a B road is a much more efficient engine speed.

[Dee_82]

I think your right about that, there is definitely a benefit to B road driving, I noticed myself doing it today, slight acceleration down the hill, allow it to bleed off on the incline, accelerate to maintain speed, lift off before you crest the hill,, coast over the top then start again. a 6th gear would have made a huge difference for the Motorway traffic.

I also think the car is generally pretty stupid in terms of fuel delivery, some times it can take quite a bit of effort getting the car to run at a good mpg, I know you have CC but I wonder if that's the same, I can cruise at 60 and get 46mpg, if I lift off a sec then apply again it can jump up to 55, fine tune the throttle by using the very end of the pedal an can get 70 on the same stretch of road. I don't think it has the programing needed run with different maps for different driving situations.

[theredfox]

was down dublin last sunday driving like miss daisy :D steady speed 60-65 both ways best i got according to computer was 46.1 mpg

think fords are way out for claiming what there models get

paul

[TomsFocus]

I think your right about that, there is definitely a benefit to B road driving, I noticed myself doing it today, slight acceleration down the hill, allow it to bleed off on the incline, accelerate to maintain speed, lift off before you crest the hill,, coast over the top then start again. a 6th gear would have made a huge difference for the Motorway traffic.

I also think the car is generally pretty stupid in terms of fuel delivery, some times it can take quite a bit of effort getting the car to run at a good mpg, I know you have CC but I wonder if that's the same, I can cruise at 60 and get 46mpg, if I lift off a sec then apply again it can jump up to 55, fine tune the throttle by using the very end of the pedal an can get 70 on the same stretch of road. I don't think it has the programing needed run with different maps for different driving situations.

Yeah I cant understand not fitting a 6 speed to a diesel in 2008, its not a town car, they're designed for motorway miles!

I think the problem there is more the instant mpg readout rather than the actual fuel delivery, it seems pretty slow to adjust so I don't tend to use it often. Somehow the average mpg works out almost exactly right over the tank.

[TomsFocus]

was down dublin last sunday driving like miss daisy :D steady speed 60-65 both ways best i got according to computer was 46.1 mpg

think fords are way out for claiming what there models get

paul

All manufacturers claim higher mpg readings as they do their tests in a lab and remove things like alternator belt to reduce engine drag etc!

However, the Focus is the smallest and theoretically most efficient turbo diesel I've owned...so it shpuld be getting better MPG than the older 1.9/2.0 diesels that I'd owned before really.