Fuel Consumption Tips

[buckets]

Hey guys,

When i first bought my skyline, i knew that petrol consumption would be a bit higher than what i was driving around (a mirage... and yes i know).

So over the past 3/4 weeks of owning the car ive managed to decrease my fuel consumption by quite a decent amount.

So here's my tips:

1: Dont hit boost (obvious, but ill explain more further down)

2: Right fuel

3: Easier driving

4: Winding out the gears

5: Using the brakes (More about caring for your car)

Now, most of you guys would know that not hitting boost can save ALOT of petrol, but what some people dont know if more vacuum pressure can also alter consumption,

and as probably everyone knows that a turbo runs off exhaust gas. If you for example, take off from a set of lights, and get top 60km/h in 4 or 5 seconds, you are going to be using more petrol than someone who would take 7 or 8 seconds.

On that note also, winding out the gears can also save you some dosh. Alot of people tend to think lower revs = less fuel used. This may be arguable but i definitely think it doesn't.

If you slowly wind out the gears to say 4500 RPM's, then due to the little amount throttle position and little amount of exhaust gas and pressure being produce, you can make it to 4500RPM without even hitting boost. Yes it will take you a little longer to get up to the speed limit, but who cares, most people take between 7 or 8 seconds to get to the speed limit. Tried to avoid stop start driving (i know this is a obvious one, but it makes a difference)

Right fuel can be one of the big winners. Even thought most of us would own similar skylines, each skyline is different in the tiniest possible way. And the difference in which petrol can make a BIG DIFFERENCE. If your mates recommend Caltex's Vortex 98, then give it a go, but dont stick with it if your not gaining anything. Its a matter of finding the right petrol that your car will like, not what a mate may recommend. Find the petrol that your car likes, and it does make a significant difference.

When slowing down, alot of people tend to using engine braking to do most of their braking. (that was a sh*t sentence lol)

Whilst this is also arguable, this is more a tip for looking after your car. What ever way you slow down, your wearing out parts of the car. People who using engine brakng are actually wearing down their engine and gearbox. Same with using the brakes, but when you look at it, a new set of brakes is alot cheaper than a new gearbox or tranny.

PLEASE NOTE:

These are my own tips and tricks i have been using, and since ive bought the car to now, ive manged to drop it from 12.5L/100km to 10L/100kms. If people do disagree with what ive said then yes do please speak up, but ive taken the time to try and provide some tips for people who are trying to save some cash.

Buckets out.

[PsYLoR]

Some good points there but the only thing I disagree with is that people use the engine gearbox to slow down because its safer then braking whilst out of gear, + if your brakes fail a least your in gear and the engine torque will help slow the car a little bit.

A 2nd hand gear box would be similar price to a new set of (good) brakes & rotos anyway.

Im sure the wear it causes would be minimal on the engine and gearbox anyway and the injector duty is always 0% when your foots off the accelerator coming down the revs. so you wont save any more fuel either way. You would just put more strain on the brakes and wear them out faster without the use of the engine. Just my 2 cents

[Randon_I_Am]

yes the driver is the biggest difference in fuel consumption.

about the engine braking, wouldn't it wear out the clutch most of all? Unless its auto of course lol.

and if you double clutch to save clutch wear, theres the lil bit of fuel used to get the engine revs up to match the lower gear... Surely its not much fuel but i wonder how much it would affect the overall consumtion?

[SHANE666]

Thanks mate, those are some good pointers. Fuel consumption makes a hell of a difference between driving styles - i.e. taking it easy or little racer boy.

[Wacky Dee]

Good points all of them BUT I'd seriously rather sell the skyline and buy a corolla than drive timidly and think about fuel all the time. It's a sports car, if you can't afford the fuel maybe stick to something less sporty.

[Birds]

Some good points there but the only thing I disagree with is that people use the engine gearbox to slow down because its safer then braking whilst out of gear, + if your brakes fail a least your in gear and the engine torque will help slow the car a little bit.

A 2nd hand gear box would be similar price to a new set of (good) brakes & rotos anyway.

Im sure the wear it causes would be minimal on the engine and gearbox anyway and the injector duty is always 0% when your foots off the accelerator coming down the revs. so you wont save any more fuel either way. You would just put more strain on the brakes and wear them out faster without the use of the engine. Just my 2 cents

yes the driver is the biggest difference in fuel consumption.

about the engine braking, wouldn't it wear out the clutch most of all? Unless its auto of course lol.

and if you double clutch to save clutch wear, theres the lil bit of fuel used to get the engine revs up to match the lower gear... Surely its not much fuel but i wonder how much it would affect the overall consumtion?

Whilst it is generally safer using gears to slow down, alot of people do this in a manner that damages their gearbox, clutch and engine. I recommend braking in gear until about 1500rpm before changing down to the next gear - this is much easier on the gearbox synchros, clutch and engine than downchanging at 2500rpm+ like I see alot of people doing. Better yet, double clutch it down...this will preserve your synchros indefinitely and is much better for your engine. A huge problem with downchanging at high rpm is you are letting the road control the speed of your engine, sending momentum in the reverse direction by spooling the engine up using the clutch. This is damaging particularly to the valvetrain and in some circumstances you can see compression lock up from it which can create a driving hazard in itself. It uses sweet buggerall petrol to double clutch because the engine has no load in neutral...I do it all the time when changing down and my fuel economy isn't bad at all.

Aiming for the best fuel economy is always going to be a balance between paying for petrol and paying for mechanical repairs. For example, too many people use overdrive 5th at inappropriate speeds. Saves them a little bit of fuel but then they have to shell out for another gearbox down the track when the teeth get stripped off the gear. Second hand gearboxes are very lucky dip too...sometimes there is a reason they are being sold and you can't test the thing until it's in your car.

100% agree with Delta Force. Buy a sports car and take everything that goes with it including the expense...

[UnCo]

Great tips Callum.

I've just started seeing how low I can get my consumption by driving very conservatively.. just as an experiment.

I think it's a matter of self control most of the time too.. other drivers take off from the lights and pass me looking over with a "why do you drive that car and go so slow" look. But it doesn't bother me

Anyway, I was averaging 13.5L/100km and when driving with fuel economy in mind, I managed to get 12.4 and 11.16.

I think driving style and keeping an eye on traffic ahead so you can keep momentum and minimise your start/stop driving helps dramatically.

I'm going to keep my experiment going for a few tanks to see how far I can wind out from a fill.. my goal is 500km from a tank without running out empty. I don't think I'll make it haha.

[buckets]

thanks for everybodys 2cents, givea me some more ideas!

one more thing i forgot to add, i've found that staying in 3rd gear while doing 60km/h does alot better than 4th gear at 60.

Most engines have it written somewhere in there ecu, what is known as a cruising speed. This speed and RPM rate is where all of the engine components work to the most postential.

From what ive found (dont quote me but) 3000RPM seems to be the cruising speed for a skyline. Well my skyline anyway. And in 3rd at 60, it sits just on 3000RPM

So if im crusing along a flat peice of road, ill now do 60 in 3rd instead of in 4th. I find that this eliminates any sortof engine struggle, by keeping the RPM at this rate.

Also, because there is very little throttle position, so there is no/little boost or vacuum pressure being created. Saving you on fuel and making you should like your flying past!

Buckets out

[mid life crisis]

i get around 500+ ks out of nearly every tank it's not hard . mine is a r33 auto standed boost a free flowing exaust / pod filter/and fmic if i dont get around 500ks out of a tank i get shitty lol . bp 98 my car seems too like best

[910trx]

if you do quite lengthy driving at higher speeds cruise controll is a must

it eliminates (well reduces) small fluctuations in the throttle which chew up fuel like twitches of the foot, and when you speed up to over 100 then back off and speed up again, it all helps

+ it prevents fatigue

also when accelerating (mostly in more underpowered na cars but the principle remains) if you are accelerating sometimes it is better to feed in throttle rather than planting it, open throttle means more fuel and more air but the engine can only use so much + it avoids overfueling and suffocating the engine giving better accelleration

some of these are obvious but there are lots of people who are completely oblivious to how to get the most out of all their cars both in economy and performance.

[Birds]

If you want a good engine RPM to cruise at in any car, get your car dynoed and going by the chart stick to an RPM range where you engine is developing a nice spread of torque.

As a general rule of thumb in manual Skylines...cruising along a flat road you are safe anywhere from 2000-2500 without putting too much pressure on engine and drivetrain components, as there is plenty of torque being developed here. Uphill I would maintain 2500-3000 depending on incline. And downhill you can be safe from 1500-2000rpm.

[Wacky Dee]

you all should just get a segway or something

[UnCo]

i get around 500+ ks out of nearly every tank it's not hard . mine is a r33 auto standed boost a free flowing exaust / pod filter/and fmic if i dont get around 500ks out of a tank i get shitty lol . bp 98 my car seems too like best

Haha it's hard for me.. my car is tuned fairly rich and even on a long trip along the Hume to Sydney my car would've struggled for 500 I think, I filled up before being able to see how far I would have gotten and wasn't keeping figures back then.

I use Synergy8000, seems to make the car feel more responsive to me.. maybe it's just in my mind though!

[Birds]

That's what a higher octane will do more than anything, particularly in a standard car: make an engine feel smoother and more responsive. So you're spot on with that one

[910trx]

That's what a higher octane will do more than anything, particularly in a standard car: make an engine feel smoother and more responsive. So you're spot on with that one

Octane is a rating given to the fuel's knock resistence, not its ability like many believe to combust differently

in a standard car which is built to run on 91 octane there will be no difference as the motor will not make any use of the octane unless you up compression or advance timing.

why you engine feels better and you get more mileage out of it is down to the fact it is more refined and their is less other crap in it

response is due to the additional timing it can run

for more modern cars or those tuned and built for use with pulp or >95 octane, ecu's take advantage of this knock resistence and often automatically wind in more timing, or in many cases just dont retard it.

this extra few degrees in timing often leads to greater fuel consumption.

the brand of fuel and where you get it from does play a huge role in how your car reacts as there may be moisture or foreign chemicals within the fuel which your car doesn't like. big servos with a high turn over are often the best to grab fuel from, the fuel is often "fresher" and there has been less time for foreign content contamination with it sitting.

just some more useless shit i have stashed away in my brain looking for a place to vent.

Edited July 24, 2009 by 910trx

[UnCo]

That's what a higher octane will do more than anything, particularly in a standard car: make an engine feel smoother and more responsive. So you're spot on with that one

Haha yeah, I meant Synergy8000 felt better to me compared to Vpower and BP Ultimate.. they just feel a tad more sluggish when I try them in my car.

[_bobo_]

i remember there was a spokesman from some place on sunrise or some morning channel while ago which gave pretty helpful tips on how to save fuel and save lots of $$$

[Birds]

Octane is a rating given to the fuel's knock resistence, not its ability like many believe to combust differently

in a standard car which is built to run on 91 octane there will be no difference as the motor will not make any use of the octane unless you up compression or advance timing.

why you engine feels better and you get more mileage out of it is down to the fact it is more refined and their is less other crap in it

response is due to the additional timing it can run

for more modern cars or those tuned and built for use with pulp or >95 octane, ecu's take advantage of this knock resistence and often automatically wind in more timing, or in many cases just dont retard it.

this extra few degrees in timing often leads to greater fuel consumption.

the brand of fuel and where you get it from does play a huge role in how your car reacts as there may be moisture or foreign chemicals within the fuel which your car doesn't like. big servos with a high turn over are often the best to grab fuel from, the fuel is often "fresher" and there has been less time for foreign content contamination with it sitting.

just some more useless shit i have stashed away in my brain looking for a place to vent.

I didn't say it would combust differently! I just said it feels smoother and more responsive - a direct consequence of the concepts you have explained here (which I already knew of)

I do disagree however, that there will be no difference to engines designed to run on 91. Even though they are tuned for 91 they can still experience detonation from time to time (particularly in older vehicles) and higher octane petrol can stage this off better. 98 octane petrol also has a longer shelf life than 91 and greater resistance to contamination, which makes a difference if the car is seldom driven.

[GTRPSI]

Hmm, some unusual ideas here.

Firstly you wont strip 5th gear cruzing on light throttle at any speed....no pressure on the gear set or main shaft.

Selecting a gear to run at a lower rpm is the preferred method to save fuel, that means short shifting, ie getting to the next gear ASAP.

Where it works against you is if you lug the engine, ie the engine speed is so low that its fighting and pinging its self to death....there is a balance, low revs, light throttle...need to go quicker, then gear down and wind it out a little.

Treat the right pedal like there is a egg under your foot, yes keep it off boost, watch the gauge, you want it as far into the negative scale as possible, whenever possible. Dont on the gas, off the gas, hold it steady like a balancing act, light small adjustments to hold your speed.

Read the traffic ahead, if you see cars stopped at the lights ahead, get off the right pedal early and let the momentum get you there while the speed washes off, you will save using the brakes as much too.

Keep you tire pressures up, to the high side, it reduces rolling resistance and saves fuel. Dont go overboard, 40 psi and your tires will wear more in the center, i run 34 psi.

Keep weight down....get all that junk out of the boot, run with 20 ltrs of fuel rather than a full tank, 40 ltrs weighs quite a bit.

Besides when you do need to give it the boot, being lighter = quicker.

Edit; almost forgot the most important thing...keep it tuned, spark and air filters must be clean.

Edited July 24, 2009 by GTRPSI

[HEKT1K]

eat less kebabs