Popular Post Roman Posted May 10, 2016 Popular Post Posted May 10, 2016 Hey people, In honor of my proud Dutch heritage, sometimes I find it to be a bit of fun to try and drive a car economically.It's pretty amazing the difference that you can acheive with some simple differences. As an example... My daily driver. Driving "normally" I will average about 5.5 litres per 100km. Driving "economically" in the last few days I can get low 4l per 100km or even dipping into the 3s.It makes the drive to work a bit more interesting, even if the financial difference is irrelevant. Regardless of whether a car is old or new there are some techniques that can help shave down that gas bill. There are a few interesting things that I've found out while trying to be as frugal as possible:1. Knowledge is powerIf you've got a non oldschool daily, that's OBD2 compliant. Get an OBD2 bluetooth unit and a smartphone app that can show you realtime and "trip" fuel consumption. Seeing the numbers as you go, is what turns the whole thing into a contest haha.If not, the best thing to do is write down results. Keep a little notebook.Fill your gas tank to the brim, and record the odometer reading each time you fill up.There is an app called "fuelly" which is essentially a digital version of this that's quite good.But having the realtime info is definitely best if you can. 2. Your car has a particular speed in top gear at which it is most economical. When you drive too slow, you use more gas because your engine is running for longer to cover that same distance. When you drive too fast, your engine is revving too high and/or the aerodynamic drag becomes too high and you use more fuel. Most cars have their sweet spot at around 80-90kph for best economy. For older cars that are a little less aerodynamic, or with 3 or 4 speed transmissions this speed may be a little lower again.If you have an OBD2 setup you should be able to keep an eye on speed and try find that best spot.If you have to take an educated guess, stick with 80kph. 2. Engine braking happens all of the timeEveryone knows about engine braking, but what is maybe not obvious is that engine braking forces happen even when you accellerate.If you are driving along on a flat road and your engine is doing 3000rpm. You've got 3000rpm worth of engine braking force that you have to supply power to, before any power can make it to the ground to help maintain your speed. If you're on a slight downhill, just chuck it in neutral. You'll not have the engine braking force dragging on your drivetrain anymore, so the only power the engine needs to make is enough to idle which is generally bugger all.2. "Pulse and glide" Relating to the above, you use a LOT less gas when coasting in neutral. So coasting for a bit, then speeding back up, then coasting etc etc is actually very economical. Especially on larger engines that may have high pumping losses at low rpm. So for example accelerate to 105kph then coast to 90, accell to 105 drop to 90, etc.You're spending a much smaller percentage of time battling against engine braking forces. As retarded as this sounds, it probably makes the single biggest difference out of anything that I've tried. Dont be a jerk holding up traffic, or nauseating your passengers with this technique.As it's quite annoying. It would also get rather tedious on a long trip. But if you're heading somewhere on your own, maybe somewhere that's a regular trip and you want to try do it on less fuel than you ever have before. This is how its done. 3. Sort the basics If your wheel alignment is terrible and you've got a half flat tire, it's going to cost you some gas. Generally pumping the tires a bit higher pressure helps with economy.Dont lug around 100kg worth of crap in the boot, you're using gas to speed all that stuff up for no reason. 4. Idle while stationary is the worst.The ideal situation is that you're going at a fast speed, with minimal fuel usage. If you're stationary then you're using gas to not travel ANY kms.Dont leave your car idling in the driveway to warm up, get in and drive straight away. Your engine uses a lot more fuel when cold, so you want to minimise the cold period and also make sure you're at least getting some kms out of it. Driving it up to speed straight away helps warm the engine up a fair bit quicker. If you're at a set of lights and you expect to be there for more than 5-10 seconds then switch your car off (assuming it starts reliably haha) 5. The brakes are stealing your economy You've used fuel in order to accelerate the car up to a particular speed, then from here you're using up your hard earned momentum to keep moving forward as the car slows down.When you hit the brakes its like you're throwing away the energy you spent fuel on.I'm not advocating avoiding the brake pedal... But the point is that if you only need to get up to 30kph to get to that next set of lights in peak hour traffic. Dont blitz it up to 70kph and then slam the brakes on right at the end. 6. Aerodynamics are your friend If you wind down your window at 100kph and put your hand out, you'll feel your arm get blown backwards quite strongly.Imagine that same force applying across the whole front of your car, you need to use a fair bit of fuel to overcome this and keep the vehicle moving forward. A more aerodynamic car (like a coupe) will use less gas than a sedan (boo) or a wagon (blergh) although there are huge variations on this depending on how much thought was put into the design.Generally speaking more modern cars have lower amounts of drag, because they started realizing it passively improves fuel consumption regardless of the drivers behaviour.The measure for how slippery a car is, is called the Coefficient of Drag (C.D.) Most modern cars have a known CD value that you can look up. The lower the number, the less fuel it needs to use to push an object of that size through the air.As an example, a Honda Insight Hybrid might have a CD of 0.26.A car designed with no aerodynamic consideration could have a CD of 0.4.If you're looking to buy a new car that will be economical at 100kph, try find out its CD value.A car with a bigger engine but lower CD value can potentially be more economical if you're doing a lot of open road driving. Anyone have anything else to contribute? Feel free to discuss anything relating to being a cheap arse on the fuel front.Thanks to some advanced driving techniques I saved about 90 cents on the way to work today 13 Quote
Popular Post Lord Gruntfuttock Posted May 10, 2016 Popular Post Posted May 10, 2016 I've found doing skids is detrimental to fuel economy... 19 Quote
Roman Posted May 10, 2016 Author Posted May 10, 2016 Just make sure you're in 4th or 5th gear to get best Litres per skid kilometer. 5 1 Quote
kyteler Posted May 10, 2016 Posted May 10, 2016 Do I have to hand in my Dutch card because I own a V8, a turbo rotary and only one of my 7 vehicles could be considered cheap on petrol and even that one I have turned into a project and ported, etc.? /slash I'll read this properly later. 1 Quote
Snoozin Posted May 10, 2016 Posted May 10, 2016 Nah you can keep your Dutch card, because on average the fuel consumption by your 7 vehicles is SFA.... 6 Quote
kyteler Posted May 10, 2016 Posted May 10, 2016 P.S. I use Fuelly for novelty purposes. FD (13BT): 15.6l/100km V8 (VH41): 15.3l/100km (unused cars) Sunny (A15): 6.7l/100km (old cars) Carina (I forget): 10.1l/100km KHR30 (L20ET): 10.7l/100km H330 (L26): 14.6l/100km E39 (I forget): 11.6l/100km) Actually, my wagon should be OK too but I haven't tracked that as yet. (I also wound the fuel up on that though, black smoke choochin') 1 Quote
Popular Post Roman Posted May 10, 2016 Author Popular Post Posted May 10, 2016 Do I have to hand in my Dutch card because I own a V8, a turbo rotary and only one of my 7 vehicles could be considered cheap on petrol and even that one I have turned into a project and ported, etc.? /slash I'll read this properly later. Imagine if some time in the future, your grand kids say "Grandpa, what was it like back when there was petrol? Did you have a car like Mad Max?" And you're like "I owned a pathetic car and then drove like a jerk to save myself an immeasurably small amount of money" Seeing them frown dissaprovingly would be awesome 15 Quote
Snoozin Posted May 10, 2016 Posted May 10, 2016 P.S. I use Fuelly for novelty purposes. (old cars) Carina (I forget): 10.1l/100km KHR30 (L20ET): 10.7l/100km I got 14.7l/100km out of the 230 when I bought it off you - after I'd fucked with the carb and sorted the timing I managed low 12's with the auto, then dipped into the 10's with the manual on that massive roadtrip we did in it. So my tip for economy in old cars - do a manual swap. Neal I'm looking at you. 2 Quote
kyteler Posted May 10, 2016 Posted May 10, 2016 Something else to consider (though you briefly touched on in another aspect) is how your wheel/tire and gear ratio combo effects things. eg. I put tiny tires on the Gloria wagon because they get it lower to the ground but it runs a 4.1 or 4.3 rear from stock, expecting a far taller tire so now my highway and indeed city revs are stupidly high and the first 2-3 gears in the manual gearbag are almost a waste of time. I'm currently at approximately a 10% diameter deficit that I will remedy by final drive alterations. Ideally I would like a 3.5 rear, this should help a whole lot. Quote
chris r Posted May 10, 2016 Posted May 10, 2016 Also re nuteral on downhills. Most obd1/2 cars will cut fuel on deceleration so you could use more having engine idling while coasting 4 Quote
Roman Posted May 10, 2016 Author Posted May 10, 2016 Something else to consider (though you briefly touched on in another aspect) is how your wheel/tire and gear ratio combo effects things. eg. I put tiny tires on the Gloria wagon because they get it lower to the ground but it runs a 4.1 or 4.3 rear from stock, expecting a far taller tire so now my highway and indeed city revs are stupidly high and the first 2-3 gears in the manual gearbag are almost a waste of time. I'm currently at approximately a 10% diameter deficit that I will remedy by final drive alterations. Ideally I would like a 3.5 rear, this should help a whole lot. Yeah I'm doing ~3400rpm @ 100kph with a 4.3 final drive which doesnt help anything. If I could find a cheap S15 six speed box and swap 6th gear over into mine. (It's possible apparently) The rpm at 100kph would drop to ~3000rpm, without adversely changing 1-5th as you would with a final drive swap. A bit more of a mission though! 2 Quote
V8Pete Posted May 10, 2016 Posted May 10, 2016 Regarding your second and third '2.'s, on cars I've had with instantaneous fuel consumption readouts, they go to 0 l/100km going down a hill in gear as the hill turns the engine over. Putting it in neutral, fuel consumption would rise to a few l/100km because the engine has to burn petrol to not stall. I don't know if that would be offset by how much further along the flat you'd get before having to engage drive again though. Also, I don't like the idea of people coasting in neutral in case the engine conks out and you lose power steering and brake boost. And if you have to power out of an emergency situation, there'll be more of a delay. e.g. when a Jafa changes lanes on the motorway when you're at their B-pillar, braking is useless and it can be better to power past them. *brmmmm redline* *bugger, I'm in neutral* *smash* 4 1 Quote
oldrx Posted May 10, 2016 Posted May 10, 2016 tl:dr, but pulse & glide works awesome (if you have a manual trans) 2 Quote
Roman Posted May 10, 2016 Author Posted May 10, 2016 And if you have to power out of an emergency situation, I ruled out this option the day I bought a Toyota Echo 2 Quote
RUNAMUCK Posted May 10, 2016 Posted May 10, 2016 One day hydrocarbons will run out. It's a likely fact. So I say better burn as much ad I can before it's all gone. I wanna use my share while I still can...... 2 Quote
Vintage Grumble Posted May 10, 2016 Posted May 10, 2016 I drive my Jazz like a nana, get some good numbers going, and then the wife will blast round town in it, and ruin everything. It seems to get low to mid 5's with normal open road driving. If you drive smoothly and at sub 90kmh speeds, it can drop into the 4's. Kinda keen to build a cardboard whale tail, pump the tyres up to 100psi, and see what she can do. 4 Quote
Vintage Grumble Posted May 10, 2016 Posted May 10, 2016 /CVT though, so never going to be a champ. Quote
V8Pete Posted May 10, 2016 Posted May 10, 2016 I ruled out this option the day I bought a Toyota EchoPowerful cars save lives. And the environment (from not being written off and scrapped). 6 Quote
Llama Posted May 10, 2016 Posted May 10, 2016 Somewhat unrelated, but its been very interesting driving around in a Tesla, because it gives you instant kWh/mile and projected range based on your current driving. A couple of times I've been caught out without enough range to get to the next supercharger (dat range anxiety), but managed to get there by driving extremely smoothly and turning off the AC, lowering the suspension and stuff like that. People have competitions to see how much range they can get out of a Tesla, I think the record is a ~2x increase in range over the EPA rated range (885km from an expected 430km, and that was only using 90% of the charge), by driving a constant 45km/h or something. I was surprised how much your speed affects your consumption. Also, I'm Dutch, and the Netherlands is planning on banning imports of consumer petrol and diesel vehicles in 2025. 6 Quote
Roman Posted May 10, 2016 Author Posted May 10, 2016 Powerful cars save lives. A good example of powering through a situation where braking wouldnt work. Would be if you were in an evo rally car, and your pace notes say that someone threw their baby in a basket just behind the next crest. You have to do a sweet jump or you'll squash the baby. 5 Quote
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