# Ways of conserving fuel while driving



## who ru (6 May 2008)

came across this and thought it was worth sharing....

http://ecomodder.com/forum/hypermiling-driving-tips-ecodriving.php


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## rmelly (6 May 2008)

Read a similar article in saturdays Irish Times I think, guys were doubling or more the manufacturers fule consumption figures. I particularly like the drafting and the freewheeling - reminds me of my mate Sid.


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## kfk (7 May 2008)

I think safety should take priority over economy. Many of the points in this article encourage otherwise.


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## mik_da_man (7 May 2008)

Yeah I've read this stuff before.
Drafting behing trucks - V dangerous
Getting up to speed and coasting or switching engine off 
Not good driving technique in my mind
Prob best to mantain a petty constant speed in as high gear as possible and avoid quick acceleration, keep windows closed and avoid using A/C

Takes all the fun out of driving IMO 

Mik


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## sse (7 May 2008)

We used to coast with the engine off down a gentle 2 mile hill when I lived in rural Northamptonshire - running cars on a showstring in those days.

One day, out of habit, my friend turned the key to turn the engine off but took it out too, of course the steering lock then came on the next time he turned the wheel (not instantaneously, we'd picked up a bit of speed).

Rather than use the brake he tried to put the key back in and release the lock - which is hard enough at the best of times with the car stationary.

Exciting few seconds that.

SSE


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## Strawberries (7 May 2008)

Piece from a site they linked to:

"Pulse and glide works like this: let's say you're on a road where you want to go 60 km/h. Instead of driving along at a steady 60, you instead accelerate to 70 (that's the pulse), and then coast in neutral with the engine off down to 50 (that's the glide). That's it.".

Wouldn't this be dangerous? Turning off the engine in the middle of driving? What if you had to brake suddenly? Your brake lights would not come on and the person behind you might not realise you are braking until they are significantly closer to you to notice! Plus doesn't coasting increase your stopping distance?


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## mik_da_man (8 May 2008)

Your brake lights would work, but your brakes might not!
Well not properly anyway, they will loose pressure if the engine is off.
Also no power steering could be a small problem too 
Quite dangerous IMO


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## jhegarty (8 May 2008)

sse said:


> We used to coast with the engine off down a gentle 2 mile hill when I lived in rural Northamptonshire - running cars on a showstring in those days.




You would lost your license on a dangerous driving charge for that...


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## ClubMan (8 May 2008)

I can see it now - _Jeremy Clarkson _hoping that these driving "tips" result in Darwin Awards for some tree huggers!


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## sse (8 May 2008)

jhegarty said:


> You would lost your license on a dangerous driving charge for that...


 
The cars were death traps, TBH, sometimes I wonder how I survived - six people in a Metro with one working seatbelt, etc. Another highlight was a friend being unable to brake because a can of deicer had rolled under the pedal!

The only thing none of us did, and this is true, was drink and drive.

SSE


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## jackswift (8 May 2008)

Did anyone here see this website [broken link removed] 
Is it a scam? My guess is that it is a scam, simply because if it was possible who ever came up with the idea would have a patent on it. It wouldn't be for sale in ebooks for €1.50 all over the internet.


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## ClubMan (8 May 2008)

Do a _Google _search for the terms "water4gas" and "scam".


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## John Rambo (8 May 2008)

jackswift said:


> Did anyone here see this website [broken link removed]
> Is it a scam? My guess is that it is a scam, simply because if it was possible who ever came up with the idea would have a patent on it. It wouldn't be for sale in ebooks for €1.50 all over the internet.


 
That's hilarious...they're basically saying a plastic bottle of water is a fuel cell! Still, my attitude is if people fall for this kind of stuff they deserve it.Imagine the look on Sheik Mohammed's face if this was for real?


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## jackswift (8 May 2008)

ClubMan said:


> Do a _Google _search for the terms "water4gas" and "scam".


 Done that over and over it brings up water4gas scam in the search. When I go onto the page it's advertising water4gas. They are mostly affiliate's pages. They know that people will search with scam so they put the word scam in the advert.


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## ClubMan (8 May 2008)

The search also returns other more independent sites that discuss the issue.


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## John Rambo (8 May 2008)

jackswift said:


> Done that over and over it brings up water4gas scam in the search. When I go onto the page it's advertising water4gas. They are mostly affiliate's pages. They know that people will search with scam so they put the word scam in the advert.


 
Try Googling Chuck Norris and hit the 'I'm feeling Lucky' button...not a scam but amusing nonetheless


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## jackswift (8 May 2008)

John Rambo said:


> That's hilarious...they're basically saying a plastic bottle of water is a fuel cell! Still, my attitude is if people fall for this kind of stuff they deserve it.Imagine the look on Sheik Mohammed's face if this was for real?


 Electric current passed through the water generates hydrogen. BMW are making a hydrogen powered car that also runs petrol two tanks. Check out this website [broken link removed]


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## ollie323 (22 Aug 2008)

The biggest fuel saving measure a person can take is SLOW DOWN! I don't mean crawl either, around 80-100kph is fine. Ok, i hear everyone saying it'll take forever to get to work. Well, next time you go to work, call up the average speed on your trip computer and zero it at the start of your commute. Now, at the end of your commute, have a look at it. I would hazard a guess that the vast majority of you will see something like 60 to 80 kph. My wife does the m1 from Drogheda at 07:15 and back from Dublin at 16:00. Her average speed is sometimes in the high 50's. Not a good average when she guns it with the best of them up to 140kph and therefore suckin diesel like its going out of fashion!! So, if everybody stuck to say, 90kph, you may even get to work quicker! I found this: 
Have a play around with the amount of cars and speeds and you'll be surprised.
Regarding the engine off coasting, it gives small gains and is risky to say the least. Engine ON coasting is safer and i've yet to encounter a situation where i have to accelerate out of trouble. I usually have to brake. 
Another fuel saving measure, pump your tires up good and hard. Grip is not compromised as anyone who remembers their physics will know that friction/traction is determined by the force between two surfaces, not the contact area.  I've had a set of  firestone f-590 tyres at the sidewall limit of  44psi for 3 years and 106,000km and i have 3mm tread left in them! I tested the grip in the wet on a quiet road (i'm not irresponsible!!) by braking hard and i stopped like a good thing. Now, if anyone here wants to flame me about this thats fine. But think about this: Out of all the car crashes you see/hear about, how many were to do with driving at or under the speed limit or skidding due to tyres pumped up to or just under the sidewall limit marked on their tyres? Not many. They were mostly driving too fast. And were not paying attention to their surroundings and giving themselves some space so they wouldn't have to brake all the time. I constantly arrive to a destination behind those cars actually. 
So, to summarise, starting with the biggest saving:
1: Slow down (the guards have been telling us this forever!)
2: Dont accelerate so hard
3: Tyres pumped up to AT LEAST what the placard on the pillar says.
4: Give yourself some space in front of you. Kind of ties in with no.1

Hope this is of some help.
Oh and about the water 4 gas, have a look at this:http://www.mpgresearch.com/forum/index.php?sid=697d544a70333370c330d0001de567c8
There is a certain amount of nonsense there but filter that out and you'll see there is a lot more going on in that field than we would be led to believe. I haven't tried the water thing but i'm watching developments. It will happen some day i can guarantee that!

Ollie


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## joeysully (22 Aug 2008)

i was off last week and decided id try to be as economical as possible for the week as i was in a hurry nowhere. as i was averaging 28MPG over the previous 3000mls i though an improvement would be easy.

so got rid of the extra weight anything that i didn't need checked my tires pressure and headed off. i was driving up and down to Kerry so not the best roads. i didn't really go slow but kept well back from other cars, this allowed me to de-accelerate and accelerate slowly when necessary. starting off at lights and junctions i did much calmer. i kept my lights on parking lights rather than on dips which i normally have on all day. 
I have an e36 318 so i ahve the MPG guage on the dash. i was watching this more than my speed and trying to keep it at 50MPG while driving steadily and not going below 30MPG while accellerating.
so the light came on eventually and calculated the average MPG to be 40MPG which i was well impressed with for a 1996 318 1.8 its much better than the manufactureres estimated MPG. But i dont think i could drive like this all the time its just toooo boring.  but as jermey clarkson proved putting an M3 up against a prius its now what you drive its how you drive it 

oh a friend of mine told me he ran out of petrol at point A here and freewheeled into a petrol station, point B, 10KM away on this route in a transit  now that fuel saving
http://maps.google.com/maps?f=d&saddr=N71+%4051.938054,+-9.657148&daddr=N71+%4051.932141,+-9.649912+to:kenmare+kerry&hl=en&geocode=14060595863331648926,51.938054,-9.657148%3B7687344476169400744,51.932141,-9.649912&mra=ls&via=1&sll=51.882478,-9.604883&sspn=0.023789,0.055275&ie=UTF8&ll=51.911238,-9.63192&spn=0.095093,0.2211&z=12


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## ollie323 (22 Aug 2008)

Good man joey! That was a good mpg increase. I hear you about it being a little boring. It took me a while to get over that and it's still hard when i'm going home off nights and all i want to do is give her holly! There's two cars in the house here and one is a diesel. My first diesel too and i have to learn how to get the best mileage out of it. Slow doesn't seem to do the job in an unmodified diesel. The engine just cools down and loses efficiency. The Drive Her On theory stands up here. However, that just consumes diesel, just not as much as an equivalent petrol car. So, how get the best from a diesel? Well, i have a theory, correct me if i'm wrong! Drive Her On seems to just work the engine hard enough to get it hot and therefore efficient. This just uses more diesel. How do i get it hot without having to floor it everywhere? Tyres are not cheap! My solution is to block up most of the radiator, about 60% so far and no overheating and no fan coming on unduly. The mpg has climbed to the EPA figure of 67mpg over a good distance. I'll block it up a little more and see how it goes. Once the fan isn't coming on she's sweet. The odd time would be ok, say up a hill or what have you. Are there any diesel mechanics out there that would know how to get the most mpg from a diesel engine? The reason i have this hot engine theory is because i drove the car hard one night for the first half of the commute and took it easy (80kph) for the second half. I averaged 150mpg on the second half for maybe 15 to 20 minutes then it steadily dropped to 50mpg. If i dont get the heat into the engine, it just wants to do 50-55mpg at any speed (except warp speed, then it drinks it fast). Truly infuriating! My petrol civic just gets better as i go slower. I just dont want to go that slow!


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## Iceman732 (24 Aug 2008)

Easiest way to save fuel: 

Only drive downhill with the engine off!!!!


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## Carpenter (27 Aug 2008)

I've being trying the "hypermiling" approach for the last couple of weeks, I don't want to state my improved economy figures just yet, I want to do a few more miles yet before I make a judgement on it.

I've been driving under the legal limit (rarely ever over 90/ 95 anyway), accelerating gradually and slowly, using the gears to slow down, allowing the engine to "overdrive" ("coasting" whilst still in gear but not applying the accelerator) when descending hills etc.  It's certainly a more "relaxed" style of driving and i'd imagine a lot safer, although I imagine it probably infuriates the one or two impatient drivers who are in a hurry and stuck behind me on the country roads I use each day!  I notice that I'm braking far less often as I can safely anticipate the road and traffic conditions ahead.  It's an easy enough challenge for because I'm driving mostly on country roads where high speed is not safe anyway, but Icouldn't imagine trying "hypermiling" on the motorway, I don't think it would be a terribly wise or safe thing to do.  Another plus I would imagine for this driving style is that it has to significantly prolong the life of tyres, brakes, suspension etc so i think I'll be sticking with it for another while!


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## Caveat (27 Aug 2008)

Not sure about diesels but for petrol cars, I've heard it said that fuel consumption increases quite dramatically if you either go over 60 mph or 3000 rpm.  

Myth?


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## ollie323 (31 Aug 2008)

Caveat said:


> Not sure about diesels but for petrol cars, I've heard it said that fuel consumption increases quite dramatically if you either go over 60 mph or 3000 rpm.
> 
> Myth?


Definitely not a myth! Air pressure goes up exponentially as your speed increases. As for engine revs, well, less is always better since more revs equals more pulses of the injectors in a given time. Think of it like you were riding a bike. It would take a lot of energy to go like the clappers wouldn't it? And spinning the pedals like mad in a low gear would equally wear you out! 
But back to cars; i find the most efficient speed in a petrol car is about 80kph. My diesel cee'd seems to (when the engine is hot) get better all the way down to 60kph when i have to drop to 4th. I got 188mpg in it between the N2 slip road on the M50 to Coolock. About 7 or 8 minutes driving. Diesels are strange beasts indeed!

ollie


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## Slaphead (22 Nov 2009)

Old thread i know but i found this article interesting.

[broken link removed]

I drive the same 60 mile route to work so i know the road well and as i normally have the road to myself and it's mainly two lane i free wheel down most hills, if i can get half a mile out of it i do it, reckon im getting 6-10 "free miles" out of it each way. But im just wondering how much petrol does a free wheeling car take?

Also for the record im very careful when i do it, i leave the motor on obviously and keep my distancee, normally doing 80-100 on a motorway or if someone's behind me i just keep the limit.


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## ollie323 (23 Nov 2009)

If your car has a fuel consumption display, set it to show the instant consumption. Then, while you are coasting you will see how much fuel you are using. Diesels seem to use approx 0.3 to 0.5L/100k which is virtually nothing. Petrols will probably use more but i'm open to correction.
The fact that they use nothing while engine braking is true, but you slow down much quicker and have to re-accelerate again. Although i did a test drive in the 308hdi recently and found it hardly slowed while engine braking. Very nice!


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## S.L.F (23 Nov 2009)

Speaking for myself I started to use Dipetane and it has certainly increased the mileage.


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## ollie323 (23 Nov 2009)

I got a bottle of that to see if it was snake oil. It did cut down the smoke and soot i get from hard acceleration after long distance nana driving, but i didn't see much mpg gains. The weather turning bad may have contributed though. I'll use it again next spring/summer and see how it goes.


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## S.L.F (23 Nov 2009)

ollie323 said:


> I got a bottle of that to see if it was snake oil. It did cut down the smoke and soot i get from hard acceleration after long distance nana driving, but i didn't see much mpg gains. The weather turning bad may have contributed though. I'll use it again next spring/summer and see how it goes.


 
Last time I went down to Cork (boating trip) I filled the tank up and put some Dipetane into it the tank lasted the complete drive down there and 3 days driving down there then when I was returing to Dublin I filled it up again and it barely lasted me getting home so for me it's an easy one I'll always use it.

Also if you use this regularly it will cut down on your emissions for the NCT (DOE in my case).


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