The Economical Driving Discussion Thread

[bl1300]

Drive smoothly. It takes far more fuel to accelerate than it does to maintain speed.

Keep your revs low but not so low as your labouring the engine and avoid the brakes as much as possible unless you drive a hybrid which has energy recovery in the brake system.

Also keep your car clean a dirty car uses more fuel as it pushes through the air than a clean one.

If your going slowly I.e around town and your too hot wind down a window rather than hitting the aircon switch on motorways do the opposite as winding down the window will increase drag and make you use far more fuel than the aircon does.

[Jizmondo Scrotmondo]

I try to read the road and get up to speed and try and get into 5th whenever possible. I mostly potter about but I usually ruin my frugal driving by eventually giving it a "squirt"

According to my 22 year-old MFA I'm doing 24 MPG.

[dodgerover]

Unloaded my van for a 200 mile run up to Derbyshire (M25 then M1) about 600kg of tools makes nearly 6mpg difference sat at 65/65 mph but 29.9mpg is still crap in my opinion for a modern 1.4 engine...we used to get more than that from the MK3 escort vans without all the fancy gadjets.

Loaded back up for the run down and got 24 mpg as usual

[welshpug]

I tend to get mid 30's from my 1.9 8 valve 205 quite regularly without trying, I seem to have unwittingly developed a very not at all slow but reasonably economical driving style

Basically involves plenty of smooth BWARP action but keeping away from the 5k+ area, doing my best not to slow down for corners etc.

On decent motorway and a-road runs where I aim for around 62 ish I have had very high 30's from tankfulls, though often a little tedious on the motorways, just turn the tunes up and watch the scenery, it is quite a challenge on the A and B-roads of Wales

[popuptoaster]

If you have an old 8v carbed car, rather than mucking about with things like tyre pressures and timing adjustments, chuck the engine out and fit a more modern one, you can often gain 10 or 15mpg AND more power and better reliability.

[AB car pix]

Apr 20, 2012 23:18:02 GMT RobinJI said:

So I've essentially just spent 45 minutes saving my self £3.36,

On the other hand, would you not if given the choice happily pay £3.36 to have the choice to do whatever you wanted with that 45 minutes of your life?

Just playing devil's advocate?

[sam1990]

Apr 21, 2012 9:30:29 GMT dodgerover said:

29.9mpg is still crap in my opinion for a modern 1.4 engine.

I agree, are you sure there's not something wrong with it? What van is it?

[RobinJI]

Apr 21, 2012 13:13:48 GMT AB car pix said:

Apr 20, 2012 23:18:02 GMT RobinJI said:

So I've essentially just spent 45 minutes saving my self £3.36,

On the other hand, would you not if given the choice happily pay £3.36 to have the choice to do whatever you wanted with that 45 minutes of your life?

Just playing devil's advocate?

That's exactly my point. I'd value my time at more than £4.48 per hour, so I would, and regularly do happily just put my foot down and burn the fuel, in exchange for getting that extra time of my life back.

My usual driving style's something along the lines of welshpugs, I try and get from A to B in a sensible time, comfortably and using as little fuel as possible, but without delaying my self. So I don't get any record breaking mpg figures, but I also don't spend my entire life in my car, which as I cover a fair few miles, is important to me.

[yankvaliant]

Install a vacuum gauge. Try to keep it reading as high as you can for the driving situation.

[DieselWeasel]

Go around corners maintaining as much speed as you can ;D

I'm not kidding; it costs less energy to maintain momentum (=speed), than to create momentum (=accelerate). So you save on fuel if you decrease the amount of acceleration after a corner. By maintaining speed ;D

Drive save, though ;D

[Count Panda]

Get a small engined car and drive like an Italian!
I am using so much less fuel in the Panda than I was in the Mercedes, but having twice as much fun!
The trick I've heard is to not bury your foot on uphill sections of road, but let the car slow down a bit, then regain the speed on a flatter / downhill bit.

I personally turn the engine off on down hills, but then I have no PAS,ABS or servo to worry about.

[Al Ramone]

well the only way I improved the economy much in my rangey was by leaving earlier for work so I wasn't thrashing it trying to get there on time ;D
improved it by 3-4mpg on a half hour drive.

oh and ref to the fuel cut on overrun on injected cars. I've found the fuel cut is only at engine revs above 2500rpm at least. that was on my 2001 mx5 engine, my 200sx engine and the 70's skyline.

so. drive slower, use less fuel.

[Fuzzy]

Although it is quite expensive to tax, I get some relief when it comes to filling up my 205 TD with diesel. I usually bumble around with little regard to efficiency and it still returns high 40s to the gallon. I went to Suffolk over Easter, did about 490 miles on a tank and there was still just under a quarter left, after doing the maths it turns out I'd done 55mpg. On the way back to East Yorkshire I didn't stray any higher than 65mph, which must've helped a lot.

If I am in an economical frame of mind, as mentioned in previous comments I find the biggest plus is maintaining momentum. Doing this makes driving more enjoyable, for me anyway; less stop-start, one continuous jaunt to your destination. Of course, after hours of doing 65 on the motorway and driving oh-so gently everywhere, putting your foot down and letting the engine chug some fuel is all the more satisfying.

It's a shame driving with gusto is so enjoyable, really.

[Vulgalour]

Just about everything I might have suggested has been covered, but one thing I've noticed since driving the Princess is that certain cars perform better in different circumstances. On a long motorway run the Princess will get much better mpg than around town and be a comfortable relaxing place to be. The Polo likewise gets better mpg in those situations, but I find myself too tense and nervy on motorways in the Polo and that affects my driving style and knocks a few mpgs off what I could get so I stick to smaller roads and journeys for the better mpg.

If you're relaxed while you're driving, gear changes, acceleration and control of the car should improve and this, in turn, improves the mpg. Strange but true. I've noted that when I'm angry or jittery behind the wheel my driving goes to pot and so does my mpg whatever the road type I'm on or car type I'm in.

A relaxed driver is a thrifty driver.

[Jowey]

Great advice given so far in here.
I'm a massive fan of thrifty driving.
I've had 52mpg out of my Arosa
and 37mpg out of my Alfa.

I'm not a genius in physics or anything so don't take what I say as golden but these are things I do/have done which I believe have/can all contribute/d to better economy.


Reduce friction every way possible
-Get narrower tires with a harder compound keep them inflated near their max

-remove and blank off the passenger side door/wing mirror or even remove both mirrors and replace them with internally mounted mirrors
(2 rear view mirrors needed for MOT)

-If the underside of your car is relatively smooth slam it to the floor
and it will reduce the turbulence of the air beneath your car,
this in turn also reduces the gap in the open wheel arch which again reduces resistance (open wheel arches are really inefficient aerodynamically)

-Buy some moondisks they look cool and they'll improve the aero qualities of your car

-Clean and then Wax the crap out of your car, a slippery car is an aerodynamic car

-Keep your trans and drive-train nice lubed up

-Check your tracking/camber/alignment tires scrubbing over the road surface is again going to cause pointless friction



Think logically about fuel usage.. when and where you buy it

-don't drive miles to save less than 2p a litre, you'll spend that getting there and back!
instead be mindful of the price of fuel, when you see it priced well, go buy some.

-Got to be somewhere? leave earlier, leave in plenty of time, If you think logically driving 10mph slower but allowing yourself an extra 10 minutes on your commute (I commute on A roads sorry to everyone stuck in traffic) think of it logically going 10mph faster will only get you to your desk 3 maybe 4 minutes earlier (depending on how far you have to travel ofc) is it really worth it ? are you going to earn the £3.47 your journey cost you in 4 minutes ? proably not.

-When you arrive at your destination and are parking your car; you are getting 0miles to the gallon.

Park your car so that you can make a quick escape with minimal maneuvers. ie take the time to reverse into the space/driveway that way when you come to leave you can just drive straight off

Reason being: your engine will be most efficient when it is running at temperature.
So by maneuvering the car into a parking space at the end of a journey it is idling more efficiently than if you were to maneuver it with a cold engine at the start of the journey

- In an ideal world we wouldnt have the need to carry excess fuel (excess weight) .you could plan all your journeys like NASA and calculate just enough fuel to get you there and back, unfortunately the roads are an unpredictable place so this isn't really plausible.


Maintain momentum:

-Need to turn left across the road? look, adjust your speed, calculate whether you need to stop if not why not just take the turn at 25-30mph?
do you really need to stop obviously be very sensible about these kind of maneuvers.

-Same as above applies to roundabouts, not a lot of use on busy ones but look, assess and look and decide if you actually need to stop or maybe you can take the roundabout at 30,40,50.. without using the accelorator
quite comical having tire squeel coming from a totally silent car.

-Leave a bigger gap between you and the traffic infront

-engine brake (fuel injected cars create a vacuum in the fuel pump when you do this so no fuel will be used at all I believe) I recommend feathering the brake pedal just enough to switch the rear bulbs on
as if a driver is close behind you they may not read your progressively slowing.





Thats enough for now..

Basically build something that looks like this:




as your daily driver
and
then drive it like its one of these:



I find driving like this really good calm fun, especially the maintaining momentum, you just glide about really smoothly

[10mpg]

Errr ok..

There's a reason I picked my username....

No patience whatsoever, an inability to consider consequences as 'real' things coupled with total addiction to driving fast wherever possible, means I get awfull mpg from everything, The only cars immune to my efforts are VW diesels...

I once tried to drive economically in my old Golf Mk4 Tdi which used to average 28-32mpg in normal commute use (10 miles of country back roads and then 10 miles of motorway each way) (which I thought was awesome mpg's!) I was forced to try this new and unusual driving style simply because I was 75 miles from home with absolutely no means of payment and the car had been on the red for 80 miles already and was now a good distance underneath the red! I actually got 72mpg! I couldn't believe it, just by sticking to 55mph (which made me want to stick forks in my eyes with the sheer tedium) and coasting down the hills by knocking it out of gear..

Just got back from California where I collected a $469 fine for speeding so after that it doesnt really matter what mpg I'm getting.

So best answer to driving economically, come with me for a drive then do the exact opposite of everything I do!

TBH for me life's to short not to enjoy yourself,

[Rich606]

Apr 21, 2012 8:55:49 GMT bl1300 said:

Also keep your car clean a dirty car uses more fuel as it pushes through the air than a clean one.

Apr 22, 2012 0:06:57 GMT Jowey said:

-Clean and then Wax the crap out of your car, a slippery car is an aerodynamic car

The difference caused by keeping the car clean will be absolutely negligible. The drag caused by the shape of the car will be orders of magnitude greater than the skin friction drag.

[speedy88]

Apr 22, 2012 0:33:14 GMT 10mpg said:

TBH for me life's to short not to enjoy yourself,

This. I did econo driving for a while. Then I felt like killing myself even though I was saving money for projects.

I HAVE switched to a cheaper car hobby though. Drifting uses far less fuel than track driving/fast road driving. Far less likely to end horribly too ;D

[Jizmondo Scrotmondo]

One thing I've always wondered, and it's probably been discussed on here at some point.

Isn't filling your car up a false economy as the car is a lot heavier with a full tank, so will use more fuel?

[djefk]

Yep, you only need to pick up a full 20l jerry can to realise! Especially if you're mostly doing shorter runs around town I think it makes more sense to stick 15 to 20 quid in at a time, It will make a negligible saving but then you have to put all these things together to get a large one!

For very long runs I'd fill up to save you having to keep stopping though.