help my mpg

[dave406]

hi all

as you know i have a 110 auto and oly get 30mpg round town i need to get more or it may have to go

[steve_earwig]

What sort of consumption do you get on a run?

[Doggy]

Fit a manual 'box?

[lozz]

Autos only do 36mpg( round town)

[dave406]

get about 30 round town and onbaord thing says avg 52 over 150 miles

[dave406]

how much does a manual get

[steve_earwig]

avg 52 over 150 miles

Is that a motorway trip or combination?

Hard to say really, I'd expect over 40 but it would get much worse if I only did trips to the supermarket and back.

[Welly]

First make sure the tyres are running approx 34PSi (2.3bar) as this helps a lot. Also a clean air filter is best. Injector cleaner might help too.

I used to get about 35mpg in my manual 110 running door to door and slushmatics are notorious for supping more juice as they 'waste' energy through the torque converter.

Lastly monitor your driving habits; braking too often is bad for economy, keeping moving is good.

[KozmoNaut]

First make sure the tyres are running approx 34PSi (2.3bar) as this helps a lot. Also a clean air filter is best. Injector cleaner might help too.

I used to get about 35mpg in my manual 110 running door to door and slushmatics are notorious for supping more juice as they 'waste' energy through the torque converter.

Lastly monitor your driving habits; braking too often is bad for economy, keeping moving is good.

Personally, I would go to 2.5bar. Going ever so slightly over the recommended pressure won't impact safety or handling, but it will improve economy ever so slightly at the cost of a little less comfort. It's a very small improvement, but it costs nothing at all.

Clean air filter, correct grade of engine oil changed at the proper intervals and generally being on top of maintenance helps as well, obviously.

Dave:

By far the biggest factor is your driving habits. Braking and the subsequent acceleration is what really burns fuel, so look farther ahead in traffic, keep a good following distance, anticipate changes in speed up ahead, try to match your speed to hit green lights instead of having to stop for red lights and always try to utilize engine braking as much as possible. Even just driving at the speed limit instead of 5-10 over makes a much greater difference than most people realize. The best fuel economy is found when going at a steady speed with the lightest possible pedal pressure to maintain that speed, try to be in that situation as much as possible. Drive as smoothly as possible, almost as if you had an eggshell under each foot. Acceleration should be smooth, but 'brisk' and with the pedal pressed about halfway at most. Accelerating very slowly burns more fuel over time, it's better to get to your target speed relatively quicker and stay there as much as possible.

Other drivers may look at you like you're an idiot for keeping long following distances and not always barging ahead at full speed, but never mind them. You're both safer and more economical.

E: To put it into perspective, I get just over 32mpg in my 2.2 petrol in mixed driving. Are most of your trips short and mostly around town? Trips like that are dreadful for any diesel, they take longer to warm up and any engine will return sub-par fuel mileage until it's at operating temperature. If that is your usual driving pattern, I would seriously suggest looking at buying a smaller used petrol car instead.

[Bailes1992]

As above really but watch the tyre pressures. I ran 37psi instead if 34psi with my Goodyear Efficientgrips and they were shot in the centre within 9000miles!

Personally I would ensure you have 4 good tyres, preferably matched across each axle and correctly balenced.
Ensure the geometry is cock on! Even if it's out slightly it can massively increase fuel consumption and reduce tyre life.
Get the gearbox oil changed, something often overlooked. This is a must ecspcially with an auto!
Engine oil should be replaced every 6,000miles/6months. Look to change to 5w40/5w30 fully synthetic.
Look into disabling the EGR Valve and clean out the inlet manifold and ports.
Decat would help improve economy also! You could probably get the standard CAT "gutted" FOC by an exhaust fabricator due to the value of the cat itself!
Look to use better quality diesels. Generally avoid supermarket fuel and maybe try some premium diesel like BP Ultimate!
Get a decent injector cleaner through the system. BG244 is a cracking cleaner! If you want something more concentrated the liquimoly diesel purge is great stuff but needs to be used neat. Have a google!
After all this, look to get an economy/mild stage one remap. Obviously you don't want to stress the auto box too much!

I personally think 30mpg around town for an automatic HDi is acceptable. That said I'm sure with the above you could make some significant improvements!

[dave406]

any idea on petrol doont wanna go smaller then astra/307

[lozz]

petrol cars arnt much better,
iirc Astra's do around 36-37. little pugs don't do much better, winters here so longer warm up times take affect imho,

My wifes car is the best ive seen so far from the petrols weve had 44-46 mpg round town and people call fiats,

[KozmoNaut]

Engine oil should be replaced every 6,000miles/6months.

What? No, the interval as specified by Peugeot (and verified by my local Peugeot mechanic with 30 years experience, including race-built Pugs) is 30,000km (18,500miles) or every 12 months. At least that's the interval on my petrol, I assume the diesels are similar. Most people only do around 20,000km/year and so are well within the intervals. Modern engine oil is amazingly stable, changing it that often is just wasting perfectly good oil.

petrol cars arnt much better

They're better for short trips, though, as they warm up faster. It's both a fuel mileage and longevity issue.

[rwb]

Well, 20k or 2 years is not frequent enough for an oil change. Mine was like powder

Keeping an eye on the MPG instantaneous readout changed the way I drive.

[Bailes1992]

Engine oil should be replaced every 6,000miles/6months.

What? No, the interval as specified by Peugeot (and verified by my local Peugeot mechanic with 30 years experience, including race-built Pugs) is 30,000km (18,500miles) or every 12 months. At least that's the interval on my petrol, I assume the diesels are similar. Most people only do around 20,000km/year and so are well within the intervals. Modern engine oil is amazingly stable, changing it that often is just wasting perfectly good oil.

Diesels are 12,000miles/12months. It's widely regarded that 6,000miles/6months is ideal for diesel engines. Even haynes reccomend it!


Manafacturers are really strecthing it out now. My fathers BMW is 25,000miles or 2 years. If you bought a car nearly 4 years old with 20k on the clock it would have only been serviced once. I'm sure that would have done it the world of good and that oil would be in awesome condition!

Considering Ford charge £6,000 for a replacement engine fitted in my Mondeo I will stick to 6month/6,000mile intervals.