I’ve noticed threads on here about fuel economy often reflect on the (in)accuracy of cars’ onboard computers vs measurements taken by diligent forum members and their ”averages worked out…with a calculator”.

But does this alter behaviour or just tell the story of how much money one pours into the fuel tank black hole each week?

My car isn’t very efficient by modern standards (though it is modern) – computer shows average of 32mpg (2 litre petrol hatchback). But it doesn’t alter my driving behaviour. I drive slow or fast depending on all sorts of other factors, but never on fuel economy.

Or am I missing a trick?

I’m always trying to keep that mpg figure as high as possible. Don’t think my current car has ever been about 72 mph.

32 is piss poor by modern standards.
I only ever drove to the MPG when me and the missus had a game as to who could get the better average driving back from the alps (it helps avoid speeding tickets) I won with the downhill 150km stretch out of the alps where it was reading high 80’s by the time we hit level ground.

If you can learn to relax and not “make progress” on every bit of road to arrive 3 minutes faster then you can change your ways. It’s more a mindset of chilling out rather than going for it.

10mpg difference between really really trying amd just driving normally.

I try when I remember.

Nope. When I first got my car I used to marvel at how it could do 55mpg. Since then, I noticed the other week it was hovering at about 46/47mpg. I get about an extra day of commuting if I drive carefully but get about 2 weeks out of a tank anyway so I’m not really that fussed. I certainly don’t let it affect how I drive. That all depends on a variety of other things as the OP states.

Last car (an M reg Micra) got ragged to within an inch of it’s life along the short but fun country lanes commute. Current car, a 3 year old Jazz, shows an average MPG and I have a blissfully relaxed drive along the flat and uphill gently easing the throttle on and off and a banzai feet off the pedals downhill twisty run all in the name of enjoying the possible economy.

Virtually no difference in journey time (it’s only 15 minutes anyway) and far greater economy. So yes, it has had an impact on my driving. Just enjoying a different challenge.

32mpg, well perhaps on a motorway cruise I might manage that. Then again I don’t do a large number of miles so the actual cost of fuel isn’t really a big deal for me.

My old 2.0 diesel used to avg about 35-40 mpg and I didnt try and improve the mpg as it appeared to make no odds.

My new 2.0 diesel averages about 60-65mpg. Has a nice display to tell you when you are recharging the battery, when the car is working efficiently etc. I’m currently trying to see if I can get to 70 mpg commuting.

Other days I drive fast and am amazed that I cant get it under 35 mpg !

My car has no MPG computer so I drive it like I stole it (joking obviously). It’s a older TypeR – I care not for this fuel you speak of! I drove lots at the weekend started out with half a tank ended with a full tank and £85 of fuel receipts!

Depends how many miles you drive to a large extent, I would think.

I commute 400 miles per week so try to keep my mpg as high as possible.
The thing is, driving faster when it’s rush hour rarely gets you anywhere faster, you just spend more time accelerating, braking or waiting at the next queue.

Before I started really trying to drive economically, 55mpg was about the most I would get over a tank and I’d be filling up around 500 miles.
Now, I can get into the 60’s fuel economy. My last tank was actually the highest I’ve ever managed. I think it was a combination of the warm weather and luck with traffic, but I managed 613 miles at 68.8mpg. And that is from an 11yr old 1.9tdi with as near as dammit, 240k miles on the clock.
Psychologically, it is much nicer to visit the pumps less frequently, even if you can leave it an extra day.

If I need to get somewhere quicker, then I will drive quicker, but generally I try to keep an eye on economy.

Yes. The lower the numbers, the bigger the grin. 😈

Yes. The lower the numbers, the bigger the grin

what ever floats your boat, I’d rather spend my cash on something nicer than chucking twenties out the window.

I certainly pay more attention to mpg than I used to. I suspect it’s an age thing though. I don’t seem to be in such a hurry these days.

It’s not usually like that. It was just a particularly demonic drive. I’ve seen worse. It bottoms-out @11mpg as fiat (wrongly) believe it won’t consume more. During the winter I can easily see 50, average B normally sits at about 35. Since I moved the fuel card to the oil-burner it’s bizarrely got worse. Presumably as i drive it so infrequently now & have to get my “fix”.

Part of the general info. on how my driving is — don’t drive to it, consciously, but happy to see the MPG in respectable territory. Return trip to Glasgow last week, incl. the dreadful A9 (dreadful as in driving standards) – shade under 40mpg, 2l petrol hatchback, is 18 years old though 🙂

These days I try and see if I can beat 50mpg on a tank full. It goes out of the window if I really need to get somewhere in a hurry but it’s amazing what being careful can do to your mpg. Coasting down hills in neutral is probably the biggest single booster. Even though I don’t have an instantaneous readout you can see the average click up within seconds.

I did manage 91.7 mpg over 33 miles last week on the M1. Pretty pleased with that.

Missus’s car has this feature. She used to aim for the magic 60mpg barrier in it.

When I drive it, I can’t see the display for some duff ergonomic reason, so generally no idea. Prob somewhere in the 40s for me.

Currently get about 52-56mpg with nothing other than brimming as a guide. On my old mans car I drive better as I like to play the MPG game 😛

Might see what Torque can throw up in the way of figures actually…

Coasting down hills in neutral is probably the biggest single booster

Hmm, for about the last 30 years, cars have been more economical on overrun in top-gear than in neutral as the ecu shuts off the fuel supply to the injectors* completely.

*carb-fed engines had this feature from about 1985.

I know that motorway runs drop my mpg in the landrover by about 3mpg per tank.

My new motorbike should do 70-85mpg i.e. 3-4x better economy and is going to be used on most personal trips where Im not carting much around.

do a fair amount of commuting and for 20 mile Mway stints the difference between 55 and 75 is marginal….its not like i am in a rush to get to work and i am still getting paid

Good run at the traffic lights make more difference than hammering i IMHO

I also find driving in the inside lane at truck speeds less stressful than having to weave to avoid middle lane hoggers and those doing 90-100 mph.
No idea what my MPG is but about 450 miles from £40- apparently that is nearing 70 in a 1.4 diesel

Depends how many miles you drive to a large extent, I would think.

I commute 400 miles per week so try to keep my mpg as high as possible.
The thing is, driving faster when it’s rush hour rarely gets you anywhere faster, you just spend more time accelerating, braking or waiting at the next queue…

… Psychologically, it is much nicer to visit the pumps less frequently, even if you can leave it an extra day.

If I need to get somewhere quicker, then I will drive quicker, but generally I try to keep an eye on economy.
Amen to all of the above. I’m quite happy to sit at sixty in the motorway if I have time, feels much MUCH less stressful, and the time it costs me I’ll make up by getting an extra day or two out of each tankful.

As som said.

I have more time and less income, if I’m economical I can go to more places. It’s that simple.

So, using the basis of a bunch of typical* STWers, it seems my devil-may-care attitude is costing me more than it ought!

I drive c20k miles pa, most of which is motorway commuting – hellish jams in the winter, and the last minute dash at fuel-inefficient speeds in the summer.

Car is a 2010 Mazda 3 2 litre Sport**. It’s worthless (well, not quite) and owes me nothing, so I am loath to change it for something more efficient until it gives me other (repairs-related) reasons to switch cars.

Hmm. Maybe time to start an austerity drive.

*I’ll let each of you reflect on whether that includes you….
**Ambitiously named, I feel, given it isn’t that sporty.

If your slogging out the miles then the basics to cover are
Comfy Seat
Good Music
Good Fuel Economy

I was getting 50’s in an N reg A4 tdi that had split climate control, nice seats and good music (when it worked) partly an efficient car helps and the other bit of not chasing the last minute of the journey. It makes very little difference.

We’ve just got a new Subaru XV. Not efficient by modern standards, 40-45mpg, and 48 if I go verrry gently on the rural roads. As its 2.0ltr and full time 4×4 I’m not too bothered. We don’t do any commuting, so we aren’t breaking the bank.

I’m sure that I can scrub a few miles off those figures, as the speed is more on the dashboard than the GPS, but that’s the way for everyone isn’t it?

I tend to find the distance to empty affects my driving more than the fuel economy.
Clocked up a big round trip over the weekend, and as I’d been driving during the day with a fair bit of traffic, so overtaking would’ve had limited effect on my overall journey, I took it quite easy. Halfway through the trip I realised that if I went easy the rest of the way I could probably make it home without filling up…

Getting the best MPG is pretty similar to caning it anyway, sort of. It’s just as if you had absolutely terrible brakes and are afraid of high gears/high top speeds.

hot_fiat – Member
Coasting down hills in neutral is probably the biggest single booster
Hmm, for about the last 30 years, cars have been more economical on overrun in top-gear than in neutral as the ecu shuts off the fuel supply to the injectors* completely.

*carb-fed engines had this feature from about 1985.

It’s an often quoted theory but it ignores a few basic facts.

While an engine may be using less fuel on the overun vs idle it will also be putting drag into the transmission which is slowing you down if the transmission is engaged.

What coasting does is reduce the engine revs to idle and allow gravity to be your energy source. It’s often possible to maintain speed or even increase it over that on your entry and coast on for hundreds of metres at the bottom before needing to engage the gears again.

Trust me it makes a significant difference. Try it if you don’t believe me.

I reckon electric cars could make very good use of it as a feature though it would depend how much energy they take to maintain an unloaded motor speed. Could be an interesting research project that. hmmmmmmmmmm

I reckon electric cars could make very good use of it as a feature though it would depend how much energy they take to maintain an unloaded motor speed. Could be an interesting research project that. hmmmmmmmmmm

The fuel economy comeptition cars do it by building up speed and then coasting for a long time with the equine turned off. Its the most efficent way to drive. Unfortunately it’s not very safe and it doesn’t work on the road.

I’ve found that coasting in gear into junctions is the biggest saver as you aren’t using any fuel on the overrun and the braking affects are desireable. Coasting down hills in neutral may be efficient but pointless if you have to brake at any stage, you may well have used the engine braking on overrun and saved the fuel you would have used ideling.

So as a general rule of thumb it would be better to always coat in a high gear than in neutral as it’s more beneficial in more situations.

gonefishin – Member
34mpg, well perhaps on a motorway cruise I might manage that. Then again I don’t do a large number of miles so the actual cost of fuel isn’t really a big deal for me.

Changed slightly above for me, do I alter my driving “style” I don’t really have a style per se’. Do I drive slower or different to save fuel, No.

The fuel economy comeptition cars do it by building up speed and then coasting for a long time with the equine turned off. Its the most efficent way to drive. Unfortunately it’s not very safe and it doesn’t work on the road.

I’ve found that coasting in gear into junctions is the biggest saver as you aren’t using any fuel on the overrun and the braking affects are desirable. Coasting down hills in neutral may be efficient but pointless if you have to brake at any stage, you may well have used the engine braking on overrun and saved the fuel you would have used idling.

So as a general rule of thumb it would be better to always coat in a high gear than in neutral as it’s more beneficial in more situations.

In gear slowing down at junctions (or wherever) is really just good practice, the most efficient way of getting around will not use the brakes at all as you’ve obviously demonstrated.

Coasting down hills in neutral may be efficient but pointless if you have to brake at any stage

I’ve not found it to be a problem and I have to brake less than you’d imagine. At the end of the day it’s effectively free speed as it’s only cost a little tickover time to get it. While I admit there will be a crossover on the graphs of each when plotted out, my experience suggests it’s more often than not beneficial.

32mpg sounds good to me, currently averaging 27mpg over the last 4000 miles, previous car was averaging 18mpg over 20000 miles.

edited to add, driving to and from work I try to drive as efficiently as possible, outside that I forget the fuel economy

jfletch – Member

I’ve found that coasting in gear into junctions is the biggest saver as you aren’t using any fuel on the overrun and the braking affects are desireable.

This is one of the things I do as a general attempt to improve observation/forward planning.
I approach a roundabout/junction and have to slow anyway. I might as well lift early, leave it in 6th and coast up to the roundabout. I sometimes use a very light brake pedal to let those behind know that I am slowing down, but depends on individual circumstance.
I also try to keep my speed up over roundabouts (not stupidly so), so I have to accelerate less on the other side. You can also brake a little harder on the approach if you see a car coming round so you can slot in behind it once it’s past you, rather than have to stop as it is ‘in your way’ and then start from a stand still.

Lots of small tricks really, mainly down to observation that can help your overall fuel consumption.
It always amazes me the amount of people who will slot in behind me for a slip road exit that is coming up and then accelerate up the slip road to the roundabout/junction 150yds away, meaning they waste fuel and have to brake harder to gain fractions of a second.

Also maintaining a constant speed helps, rather than yo-yo-ing around a desired speed. I was behind a woman driving yesterday who appeared to be having quite an animated conversation with the bloke in the car with her. Every time she got more animated (arms waving around) she lost about 5mph, which she would then regain by accelerating back up to speed and then slowing down again.

God. That all sounds well boring!! I do enjoy giving it the beans but to be honest on my commute there is little point or enjoyment in doing so!!

jfletch – Member

I’ve found that coasting in gear into junctions is the biggest saver as you aren’t using any fuel on the overrun and the braking affects are desireable.

I do this as well. Now we all know it’s wrong and we would fail our tests again, but we just do it.. Does anyone do it on long hill descents?

Sui – Member

jfletch – Member

I’ve found that coasting in gear into junctions is the biggest saver as you aren’t using any fuel on the overrun and the braking affects are desireable.

I do this as well. Now we all know it’s wrong and we would fail our tests again, but we just do it.. Does anyone do it on long hill descents?

Coasting in gear is the recommended technique as far as I know. Are you mixing that up with coasting in neutral?
It used to be recommended that you changed down the gears as you slowed to use engine braking and so you are ‘in the right gear’, but I think the teaching now is more along the lines of slow using the brakes (which work a lot better than they used to), and then change gear when you get to your desired speed so you aren’t doing two things at once.

Just out of interest, on my VW, when I’m effectively coasting down a hill or whatever the MPG rate goes to 199 I think then maxes out at “—“

does anyone know whether that “—” contributes towards the average or is ignored?

I’ve always wondered whether to get the average up (just for the hell of it) its better to keep the foot on the gas a little and keep it out of the ‘max’ zone??

I’ve always wondered whether to get the average up (just for the hell of it) its better to keep the foot on the gas a little and keep it out of the ‘max’ zone??

That — just means you aren’t using any fuel so the fuel economy can’t be calculated as it’s dividing by zero or you are beyon the capacity of the display, i.e. higher than 199.

Not using fuel is the best way to get the average up!

It maxes out because you’re moving and using no fuel so you’re doing infinity miles per gallon instantaneously. Annoyingly the engine and transmission drag is slowing you down far faster than you would be in neutral so while it’s a good thing to do when coming to a halt as it’s free braking, if you weren’t coming to a stop, you’d probably have lost out.

agreed. so all those maxed out miles don’t count towards upping the average??

Aww- that’s not fair!

(I know in reality they do of course, but for playing the ‘game’ its a bummer)