Quote from Mille Sabords :

I spend a few days in Malta some years ago and the bus drivers have an interesting fuel saving technique:
Put it in neutral as soon as you reach the desired speed. Never brake except in emergency situations. Traffic lights are an indication vaguely similar to "use some caution when red".
Efficient but scary?

I once called a cab in Malta to pick me up from a festival. The guy arrived in no time at all. I said "Wow, that was quick", he said "Yeah I drive too fast", put his car in reverse and floored it. Through a festival crowd. On the way he told me he didn't usually work evenings and he'd been watching TV at home drinking whiskey when I called.

Quote from the_angry_angel :

I don't see why?

Really my annoyance of people who do this is as a passenger of people who think that the car stuttering on stalling up a hill in top gear with full throttle open isn't a complete waste of fuel, very slow and uncomfortable.

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I've seen no evidence as such to be honest

Near the stall threshold most engines will not run smoothly and the knocking effects that causes are like a scaled down version of ignition problems/rough firing engines in racing cars that can rip drivetrain components apart.

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Nope, there's a marked increase in the cars I've owned over the last few years. Even my '97 petrol Clio would be better off coasting in gear than out of gear I'm afraid.

Coasting in gear will not allow you to travel nearly as far as coasting out of gear. In order to go as far in gear you need to either apply some throttle or let the car return to idle revs and let the computer then open the throttle to maintain idle speed. Of course the best option would be to switch the ignition off but unfortunately given the now virtually standard fitment of steering locks it's no longer always a safe option.

Quote from ajp71 :

Coasting in gear will not allow you to travel nearly as far as coasting out of gear. In order to go as far in gear you need to either apply some throttle or let the car return to idle revs and let the computer then open the throttle to maintain idle speed. Of course the best option would be to switch the ignition off but unfortunately given the now virtually standard fitment of steering locks it's no longer always a safe option.

I remember doing that one once, luckily I was in my driveway and wasn't moving to fast. Did teach me a valuable lesson- coming up to a corner and not being able to turn really sucks, even at slow speeds.

@Up above - I think staying in the highest gear and using full throttle would use more fuel than if you were in a normal gear using 20% throttle... But I don't know much about how fuel control systems are working, just a thought I've always had.

The Volvo does all it can do to try and save fuel. It changes up as soon as it possibly can (well, if you're in the first third of the accelerator travel) and it seems to cut or severely restrict the fuel flow when costing on the flat or going downhill (the instantaneous mileage display on the trip computer goes up to 99.9mpg). I get an average of about 25mpg when I do my normal work routine (i.e. 15-16 miles a day of brisk country driving and plodding about town). When I get on the motorway I get about 35-40 depending on the speed and conditions. Tank takes about 70 litres and I like to use BP Ultimate (think it was 112.9 per litre last time I filled it). It's a thirsty bugger but worth it when the throttle meets the carpet

my dad (and now me) usually drive UNDER the constructor's annouced millage: for my dad's 10y old Saxo, the mileage is (sorry, but youll have to convert) 5.5l/100kms.
My dad manages 4.7/4.9/100kms. This in-city driving (but not stop-n-go driving, just regular, empty roads city driving). This is taken from the last 100THOUSAND kilometers, so should be pretty accurate.

I do with my Xsara picasso (also a diesel) 6.0l-6.5l/100 - constructor says its 6.5l/100. But I got more of a lead foot than my dad.

How? (keep in mind these are diesels).

High tyre pressure (also helps decrease tyre wear)
Mid-75% throttle on accelerating (like out of semaphores).
Keep the revs in the mid-range (in the saxo, around 2.5-4.5k (goes from 1k to 7k), the Xsara doesnt HAVE a rev-meter).
Get to top gear, and COAST. Putting it in neutral uses MORE fuel than just letting it coast in gear. Thats cause when in neutral, it needs a dab of throttle to keep the engine going. When coasting in 5th, the wheels are pushing the engine, so it uses _no_ fuel AT ALL.

Thing is, when coasting in gear you will be decelerating, so if you want to go long with a near-constant speed, THEN use neutral. usually, though, you will want to keep coasting.
Never ever ever EVER brake. Coming up to a red light? Keep shifting down and let the good'ol engine brake for you. All the way down to 1st (where you will be going @ 5kph), then neutral and just brake when you'r at 1kph.
- think of it this way, since the engine is braking for you, it doesnt use any fuel. When you consider you will have to brake nearly 500m BEFORE the red light, think that you will be doing those 500m FOR FREE.


Also, if you got a diesel, consider filtering and re-using your frying oil I know for a fact it works on just used frying oil, I just dunno if it would work with a diesel/oil mixture.

If you have a modern diesel, then do NOT use filtered frying oil. The tolerences on the high-pressure diesel pumps are such that the lack of lubricity will cause a siezure, and they aren't cheap.

If you have a diesel that is about 12 years old or more, then you MIGHT get away with it for a bit.

I still wouldn't recommend it though, unless you mix in proper, refined diesel in a 20:80 mix (80 for real fuel), and even then it still might break...

Quote from Stigpt :

- think of it this way, since the engine is braking for you, it doesnt use any fuel. When you consider you will have to brake nearly 500m BEFORE the red light, think that you will be doing those 500m FOR FREE.

500m? Are you braking from 200mph on ice?

The car doesn't use no fuel when coasting, it still puts enough in to keep the engine firing, although there's probably no reason why a modern ECU couldn't be programed to completely cut off the fuel supply when coasting. Also bare in mind that coasting in gear is only more economical than running in neutral in cars with modern fuel injection systems.

Quote from ajp71 :

500m? Are you braking from 200mph on ice?

The car doesn't use no fuel when coasting, it still puts enough in to keep the engine firing, although there's probably no reason why a modern ECU couldn't be programed to completely cut off the fuel supply when coasting. Also bare in mind that coasting in gear is only more economical than running in neutral in cars with modern fuel injection systems.

Modern ECUs do cut off the fuel completely (for petrol engines at least) and don't do the ingnition thingy.

Quote from danowat :

I generally get 56mpg out of my car, it will be interesting to see how many extra mpg's hypermiling techniques will give.

I'm not sure if this is what you mean with the term hypermiling, but I managed to get 18% more mileage in my Peugeot 306 1.4 (petrol). Went from an average 850km on a (~64L) tank to a - to me -astonishing 1100,8 km. Was well surprised by what driving-by-head instead of by-heart can do! I made a list for a similar discussion on our team forum, thought I might as well post it here. With the crazy fuel prizes these days I think everyone will be interested in trying to get a better mileage our of a fuel tank...

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Here's some of the stuff I did to get a lower fuel consumption:

1 shift up uber early, a good estimate was gear = speed/10.
2 shift up uber fast too, this way you'll avoid losing both engine and vehicle speed
3 brake very late for stopping lights and etc.. just to keep the option of a green light, or other immediate crossing opportunity open (ie. not having to slowdown and most importantly speed up again)
4 always try to keep the car rolling when approaching stopping lights or other crossings.. resistance is highest when you try to get the car in motion after a standstill
5 when approaching a crossing or traffic light, etc. let the car roll out in gear. In this case the wheels even drive the engine, instead of the other way round, so assuming my MMS is programmed to not inject fuel when no power is asked (every new-ish vehicle is programmed this way) this is a much better fuel saving method then letting it roll in neutral gear. You can optimise this method by using every gear while rolling out, so 5-4-3-2-1. You know when to shift down when you feel the engine starts getting a grip on the wheels again (preferrably a tiny bit before this point of course).
6 when accelerating, try to apply as little throttle as possible, but don't exaggerate: too little throttle (e.g. when engine starts shaking) makes for a worse combustion and thus increases fuel consumption!
7 slipstream trucks and busses on the highway to the extent that (mostly female) passengers wanted to get out soon as possible
8 keep a high cornering speed to avoid having to speed up after every turn (this is where the fun has to come from when you are on an other than that incredibly dull save-the-environment-and-my-money-tour)
9 with regards to the above: try to drive the ideal (race) line through corners. this means higher corner speeds are possible and - if driven fluently - results in less stress on the vehicle's supsension and tyres (less resistance -> better mileage)
10 shut down the engine immediately when you arrive at your destination
11 don't start the engine until you're actually ready to drive
12 keep electricity consumption as low as possible (preferrably don't charge phones in your car, only switch lights on when absolutely necessary, etc.) this way your alternator can run on a lower intensity which results in lower fuel consumption. best would be to use no radio either, but that would really kill me. During this challenge I had it loud as always :P
13 keep windows closed as much as possible; less aero drag means less fuel consumption
14 last but not least: don't drive too fast. I never did faster than 120 km/h on this tank, not even on highways. Normally I at least have one trip where I drive 150+ for longer periods of time. This of course means higher revs, but much more important: much higher air resistance (this increments exponentially over higher speed). So keeping a slower pace on the highways (and preferrably in the slipstream of bigger vehicles) can save you massive amounts of fuel. I also did lower speeds on the normal roads: just about 78 km/h where 80 is allowed, etc. (all this sometimes to the annoyance of the cars behind me, but then I thought about how many times I have been stuck behind a slowpoke and it actually felt good :P)

Please note that some of the applied methods of course have negative effects on other parts of the vehicle or my money (ie. drive through the red light (€130) on an empty crossing, just to avoid having to speed up again, or take a 90 degree left turn with 80 km/h for the same reason... (suspension and tyre wear: €€€), etc.)

Just for the record I'd like to put a little disclaimer here: if you try some of these (potentiall dangerous) methods and something goes wrong, please don't blame me!

I am currently halfway through a tank of diesel using hypermiling techniques, currently my odometer is reading 390 miles, which roughly equates to about 60mpg, about a 6-7% increase.

Last tank of gas in my Saturn I got about 19mpg or so. But every single day that I drove it, I floored it to 60mph at least three times. And the Saturn S-Series tends to run rich when you floor it. I think my spark plugs need to be replaced though. Oh and the last day I was driving it, I floored it to 75mph so I could get some air off of a hill. Don't worry, it was in a very rural area. I also went down a gravel road at 35-40mph. I found out that my new Pirelli front tires are no-where near as good on gravel as the old Michelins. But my huge 250lb+ friend rides a 50cc moped to school. He gave me a ride home on it yesterday, it gets really good fuel economy. Except later that day the sprocket on the wheel got stripped of all it's teeth (most likely from all the weight). Why try hypermiling if you can just ride a moped?

Because it rains too much here

Rule number one: Anticipate your driving!
Try to keep your eyes far enough and analyze the traffic all the time. If you see a light going red or brake lights lid 10 seconds ahead of you, start coasting, and try to aim for the maximum possible speed when you can start accelerating again.

Accelerate at least on half throttle, and jump gears if possible. Revving on 3rd to cruise speed and then changing to 5th is more efficient than going 3 -> 4 -> 5.

On highway or A-road lift a bit on downhills and gather more speed BEFORE an uphill, so you don't have to give more gas at the hill (=more load, bigger consumpion).

Vegetable oil in diesel. My little brother dilutes his like that. Sure, you won't break any 0-60 records, but it'll run.

Plenty of articles to read about in on Google.

Quote from herki :

Modern ECUs do cut off the fuel completely (for petrol engines at least) and don't do the ingnition thingy.

Actually you're right, after a bit of experimenting I've come to the conclusion there's no change between coasting with the ignition on or off in the Focus.

Quote from Dajmin :

Vegetable oil in diesel. My little brother dilutes his like that. Sure, you won't break any 0-60 records, but it'll run.

Plenty of articles to read about in on Google.

Not wise for those of us with new-gen common rail diesels, it can ruin the high pressure pump (6000psi I was told :really and they cost upwards of £2K (again, so I was informed)

This topic is interesting, but... Call me stupid, isn't coasting in gear/cruising in neutral inherently dangerous?

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But never coast to save fuel; vehicle control must not be compromised.

^ Above from advanced-driving.co.uk

Quote from TiJay :

This topic is interesting, but... Call me stupid, isn't coasting in gear/cruising in neutral inherently dangerous?

Why would it be any more dangerous than driving in gear? , aslong as the engine is running it's just the same.

Quote from danowat :

Because it rains too much here

Wimp.

You could look as cool as me on a bike!

Wait, now I see why you don't...

Hehe, you've seen the pics of me when I was about your age!!!!

I would use my bike as daily transport, but it uses twice the fuel my car does!!! LOL

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Why would it be any more dangerous than driving in gear? , aslong as the engine is running it's just the same.

No engine braking I guess? Also, wouldn't the car just gradually slow down?

No ability to accelerate without putting it back in gear also.

For the record, I only coast in gear, as it uses less fuel than coasting out of gear

Just ftr my bike only gets around 60 - 65 mpg (although I probably worked it out wrong), it's not really worth looking like a tit for.

A 125 or something would probably be the most economical way to do things...

Just worked out my fuel economy over one tank of fuel- 34mpg from a 1.25 Fiesta Zetec. I should probably work on this efficient driving thing...