MPG shite

[Roverageous]

I presume with the interest shown at various times on the forum to diesels and veg running that running costs /mpg is of interest to a selection of shiters. If it’s not, please ignore,

 

From time to time I enjoy a good MPG challenge, and I’m subject to the constant chatter from my father on the subject. In fact just today I have managed to eek out 37 mpg from my notoriously thirsty Rover Kv6 75 - this is over 319 miles and no motorways in sight.

 

My technique differs from my Dad’s and is a point of much (friendly) contention. I am firmly of the opinion that acceleration should be as swift as is possible to cruising speed (notwithstanding situations where you know you will need to slow again shortly). Once at cruising speed this should be maintained with as lighter foot as possible, and what REALLY matters is the slowing down.

 

To this end I try and read as far ahead as possible, and try not to use the brakes when unnecessary. When slowing for a roundabout I will try and use engine braking as much as I can with a light foot on th brakes just to illuminate the brake lights.

 

Dad, on the other hand, firmly believes that acceleration should be a max 1/3 throttle travel & cruising at 55 is the way forward.

 

What’s your technique?

[DodgeRover]

Tuck in behind a wagon and hope its not one of Asdas running at 45mph on the limiter....

[Stanky]

It drives me mad, but 'burn and coast' enables me to eke out 45mpg in the Saab. Rev to 75mph, then coast with no throttle until speed drops to 55mph, then repeat.

 

It is most easy to achieve on a quiet dual carriageway.

[uk_senator]

I try to cruise at 56mph eveywhere, police rarely understand that in central London. I also avoid braking & read the road well in advance, which often pisses of drivers behind me (who I generally end up overtaking after they`ve impatiently overtaken me as I`m cruising towards the red light that they`ve overtaken me to get to quicker than me).

[bunglebus]

I treat all the pedals as if they have a raw egg between them and my foot. Usually 60 MPH on cruise when on motorways/dual carriageways, and reading ahead for traffic lights, slowing cars etc. I know the behaviour of local traffic lights and can predict whether to go for it or coast when approaching them. There are also a couple of bits on the A45 where I can put it in neutral and it will stay at 60MPH due to the decline.

I got 65 MPG out of the last tankful (1.9 TDi Passat). 56 is about the worst it's given with mixed town/M-way driving.

[pshome]

I get excellent mpg by preferably using downhill roads...

[Fabergé Greggs]

You can always have a little fiddle with the odometer too, heres' a simple guide:

 

Backwards= Less MPG, more resale value

Forwards= More MPG, lower resale value.

[Pillock]

I primarily use roads with roadworks featuring 50mph average speed cameras, set the limiter to 54mph which juuuuust about lets me use 6th gear (=1100rpm) until I get to an incline. 

[cros]

Fuel cat

Plus magic inlet manifold device

 

 

Plus spark boosting thing

= so much economy that with careful driving you'll actually be manufacturing petrol.

[Twiggy]

To achieve maximum mpg  it`s vital to keep the vehicle in as good a condition as possible. Service according to manufacturer`s schedule, check tyre pressures regularly, have the tracking checked, and make sure that the brakes aren`t binding. Follow all the excellent tips about driving in the foregoing threads and remember that using the brakes wastes fuel !

[gordonbennet]

You can spot a properly driven car/van/bus/lorry that gets good mpg anywhere, disc braked wheels won't be caked in ingrained brake dust, have a look see how many vehicles of any description have clean disc braked wheels.

 

Agree with the above posters, why people are on the throttle right up till the last second then have to brake like buggery...when anyone looking further than 20ft in front of the bonnet could see a queue ahead...will always be a mystery, i tend to the steady speed cruise, not as i can get much above 25mpg general running about from the Landcruiser.

[John F]

I ignore MPG entirely & concentrate on enjoying the drive

[twosmoke300]

I think for everyday economy you have got a job to beat a vag 1.9PD but unfortunately that means driving one .

My wives octavia will do 50 mpg even with her driving trips of less than 5 miles around cornwall .

I can usually beat her mpgs by at least 5 by driving more carefully . 

[bunglebus]

To achieve maximum mpg  it`s vital to keep the vehicle in as good a condition as possible. Service according to manufacturer`s schedule, check tyre pressures regularly, have the tracking checked, and make sure that the brakes aren`t binding. Follow all the excellent tips about driving in the foregoing threads and remember that using the brakes wastes fuel !

 

Service every 6k, not the ridiculous 20k the manufacturer recommends!

[Rusty_Rocket]

No special technique needed. Simply drive everywhere in a 106 1.5D. Bosch pump for durability, but I found the Lucas ones slightly more economical.. 

[Rave]

To this end I try and read as far ahead as possible, and try not to use the brakes when unnecessary. When slowing for a roundabout I will try and use engine braking as much as I can with a light foot on th brakes just to illuminate the brake lights.

 

Dad, on the other hand, firmly believes that acceleration should be a max 1/3 throttle travel & cruising at 55 is the way forward.

 

What’s your technique?

 

Petrol engines are (theoretically at least) most efficient when running WOT. If you were insistent on doing every journey in the exact same set amount of time, then accelerating WOT (through the engine's torque peak) and then cruising at 55mph would be more fuel efficient than accelerating slowly up to a cruising speed of 57mph.

 

In reality, accelerating gently up to 55mph uses the least fuel at the cost of a trivial amount of time. Because I'm an idiot, I own the least fuel efficient car in my particular model range (a 3.0 V6 Mk3 Mondeo estate), and because I'm rarely in a hurry I usually try and maximise it's economy by doing long journeys at 55-60. Because of the aforementioned efficiency at WOT though, I don't feel bad if I give it the beans down a motorway sliproad.

 

Edit: I like to drive with the cruise set to 60-ish in the inside lane, but if I'm overtaking someone doing a slightly lower speed I give it a quick bootfull to get past rather than sit for ages in the middle lane slowly inching past, bunching up faster traffic behind me. Because of the 'pulse and glide' effect that seems to make almost no difference to the economy showing on the trip computer.

[Guest Hooli]

I try not to brake, but that's just reading the road properly as others have said. It gets me 28-29mpg from the Saab in normal use & 39mpg on a long run.

[Lacquer Peel]

At 0p/litre I'm not too bothered.

 

/smug

 

Aye, the most efficient way to drive is by planning ahead. I coaxed 55MPG out of one of the new Transits, albeit by resetting the computer on a long A road stretch.

[LostnotFound]

Service every 6k, not the ridiculous 20k the manufacturer recommends!

 

I'm not one to knock fuel savings, but are you saving a tanks worth of petrol every time you service the car to make up for the cost?

 

People don't like looking more than 20ft in front. Hence why more and more people drive as if there is a magnet on the bumper of the car in front, with no thought to overtaking if it's clear ahead, or knowledge as to why you might as well leave a gap given we all should be able to see the queue of traffic miles ahead on this straight road.

[reb]

A couple of weeks ago I managed to get 63mpg average on the display at the end of a night of work so 95% town driving. Achieving this required keeping the revs below 2k as far as possible, rarely using the brakes and doing very little stopping. I used a tiny amount of fuel and my delivery times didn't suffer (already one of the better in the store, hustle on your feet not on the street and all that, the less time I spend mucking about the more driving time I have so I don't need to go fast).

However on the drive home I booted it out of a 30 and the car behind me disappeared in a cloud of healthy* black smoke.

I've not repeated the experiment.

 

Sent from my SM-G935F using Tapatalk

[Lacquer Peel]

The distributor pump TDIs are incredibly fuel efficient, why bother with common rail or unit injection?

[bunglebus]

I'm not one to knock fuel savings, but are you saving a tanks worth of petrol every time you service the car to make up for the cost?

 

 

 

Probably not, but I'm too old school to bear the thought of 20,000 on one oil change. I guess you could say it saves me money long term as the car should last longer.

[DodgeRover]

Unless your sump holds 10+ litres of oil or you are just doing continual motorway work 20k miles between services is only going to cause early engine failure.

Have some oil analysis done every 5k miles to see how it's breaking down.

[LessThanEqual]

I was amazed to see 65 mpg, tank to tank, from my PD Ibiza. I do nothing but just drive it.

[PiperCub]

You can spot a properly driven car/van/bus/lorry that gets good mpg anywhere, disc braked wheels won't be caked in ingrained brake dust, have a look see how many vehicles of any description have clean disc braked wheels.

 

Agree with the above posters, why people are on the throttle right up till the last second then have to brake like buggery...when anyone looking further than 20ft in front of the bonnet could see a queue ahead...will always be a mystery, i tend to the steady speed cruise, not as i can get much above 25mpg general running about from the Landcruiser.

 

Exactly what he said!

 

Add into that, looking ahead and planning what you are going to do in advance. The idiots that are always on the brakes and stop at clear roundabouts when they can be smoothly negotiated with just a slackening of the throttle. All the stopping and moving off is really wasteful of fuel and wears out clutches, tyres etc when it isn't necessary.

 

Also, paying close attention to maintenance esp wrt to filters, oil & general running gear plus checking tyre pressures once a week along with the underbonnet checks goes a long way too. 

[JayW]

I drive a 4 litre Jag daily, MPG is meaningless when it's as low as my regular 17...

[Guest Hooli]

I drive a 4 litre Jag daily, MPG is meaningless when it's as low as my regular 17...

 

Luxury! my old 3.2 averaged 16.6...

 

Managed 26.6 on a run mind.

[lisbon_road]

Worth checking the odometer in the car against the km posts on the motorway.  Tyre wear makes a difference.  And keep to sensible narrow tyres.  

 

All good advice above, generally keep the speed down.

 

I get over 50mpg out of my Astra on petrol and 40 on LPG.  It fascinates me how people often seem to get far worse figures.

 

Of course, don't ever believe those car fuel readouts.  Often 10% out.  I've tried a few, though a friend's Honda Jazz was spot on.  

[Skoze]

I live 5.5miles from my girlfriend, my Jag just about managed two there-and-backs on a tenner. 

It also emptied the tank at an alarming rate trying to cruise at 55mph rather than its preferred 90 70 on its last motorway run which leads me to believe all the trickery is bollocks beyond a certain calibre* of vehicle. 

 

I can't wait to pick up it's 306 turbot deasal replacement tomorrow. 

[jonny69]

Best way to get top mpg is to own the most fuel-efficient car ever built. Mk1 Insight. I get 72-76mpg per tank, typically. Does about 72mpg at 70mph, 84mpg-ish at 60 and best I've done for any stretch at 50mph sitting in lean burn is 114mpg.

 

On that car though, efficient driving is quite different. You can use the battery to accelerate and the motor can be used in regen for deceleration - which you just use next time you accelerate. Though it is better to not change your speed at all and try and keep it in lean burn mode.