Cruise Control ?

[gillyallan]

Ok been a 300 mile trip today and averaged 55.2 mpg over the distance. Most of the motorway journey I did under cruise control of which I'm new to.

My question is. Is it possible you'd actually use more fuel under cc ? Ie if you are under control and know a big Hill is coming you can build up some speed beforehand, whereas the cc only reacts as it hits the Hill.

Also under cc, is it braking on downhills to hold you at that speed ?

Just curious on opinions. I did enjoy the journey under cc though.

Now I'll need to spend tomorrow on fly removal.

[Willy]

There's no braking with cruise control so you will pick up speed going down hill, cruise control will only cut power till you get to the set speed again.

I'd like to think cruise control help fuel economy in my opinion.

[iNath]

I can beat cruise control mpg using my right foot ;)

[gillyallan]

I rekon mpg wise I could beat it too. However the beauty of cc imo is the consistent speed. It's so easy on long journeys as it goes on to drop your speed without really realising, whereas obviously cc is like the viagra of the car world in keeping it up over a long period.

Over a distance What's the best mpg folk have had out our little ecoboosts ?

I had 2 adults and 2 kids in for my 55.2 over 300 miles. I have been debating my rear tyre pressures into the bargain and think I should raise them a little. Unfortunately the fiesta seems to have so much recommended variance on rear pressures depending on load. I think I'm running at 28.

[Gary.J]

There's no braking with cruise control so you will pick up speed going down hill, cruise control will only cut power till you get to the set speed again.

I'd like to think cruise control help fuel economy in my opinion.

Of course there's engine braking with cruise control on hills. If the car is travelling faster than the speed set for cruise control, the fuel flow is reduced and so the engine is being driven by the wheels, hence slowing the car down until it goes below the cc set speed. If the hill is steep enough, then you'll accelerate whether you're using cruise control or not but it will be at the same rate regardless.

[Willy]

Not going down hill is doesn't. Fuel is cut but the car will still pickup speed until you apply the brake.

Find a nice long hill and see if cruise control keeps the car at a constant speed as gravity is pulling you down it.

[GlynnZS]

As Gary said, Cruise control cuts fuel, which instigates engine braking, which helps to keep the car at the set speed downhill, unless the hill is steep enough to create more gravitational pull than it takes to turn the engine, in which case gravity will make the car speed up. All depends on the gradient.

The little 1.0L doesnt have very much engine braking, probably because its 3pot and doesnt take much to turn the engine over. The ST has a fair bit more engine braking.

[Willy]

The 3 pot has virtually no engine braking ;)

[AllenP]

I have a new Tit X automatic and although too soon to get truly meaningful mpg figures (@600 miles) my mpg to date is 45.

80% of the mileage has been on long runs with motorway or dual carriageway for at least 50% of the journey.

- Using cc set between 60 and 70 improves mpg dramatically (as shown by on board display) when travelling on flat or downhill (not lower than 60) but plummets to 23-25 when going uphill. Overall cc improves mpg on the automatic as well as being more relaxing.

- I agree that engine braking seems less on a 3 pot motor. When going down a steep hill I first change into S mode to keep the gears lower and engine revving higher. As my speed increases due to gravity I manually change down even further giving me some engine braking though not as much as with a 4 cylinder manual gearbox. I often find that I need a dab on the brakes half way down if I have to comply with a 30mph limit.

[gillyallan]

Where do they test the car to get the books 60 odd mpg ?

As I said I managed 55 running mainly about 65 mph. I very much doubt even by myself id get in the 60s. I also rekon my car is happier running at 65 mph rather than 56 mph.

Maybe the 125 overall would return more than the 100 too.

Don't get me wrong in not complaining about the mpg. I'm just being geeky with an interest in it.

[DaveTheDog]

Snip............Over a distance What's the best mpg folk have had out our little ecoboosts ?

I had 2 adults and 2 kids in for my 55.2 over 300 miles....Snip

I recently travelled down to Fowey in Cornwall and got 57mpg @ a steady 70.

Used cruise quite abit but it's a PITB when it's busy.

[GlynnZS]

In my ZS I managed an indicated 62mpg one day on a trip to work. My car was happy sitting at 31mph in 5th gear at 1000rpm ish, which I know some people's aren't. I was very lucky with traffic light timings and it was about 10pm as I work nights so traffic was minimal. I just sat at 31mph on the 40mph roads on my route for 10miles, 2 or 3 stops at lights and the car showed an instant mpg of 80ish, and avg 62.

I was very short on money and petrol that day, all other work journeys achieved about 42mpg and weren't done at 31mph!

Obviously the mpg test is done on a rolling road, but I bet it has a lot of sitting at 30mph in 5th gear on it to achieve 67mpg.

[GlynnZS]

I had to Google PITB, and the first result was Punjab Information Technology Board.

I feel old :-(

[potter18]

My car doesn't have cc but on a summer holiday down south (york to dorset) my mpg was 54 going down and 59.3 on the return , keeping to motorway speeds where poss , (10l ecoboost)