Modified Car? How Bad Is Your Fuel Economy?

[Sklyn]

If you were to state your vehicle, then using "per tank" is fine as its consistent.

actually its not fine, fuel gauges are not very accurate and i would hope you don't run it dry so you are really just having a wild guess. You might still have 150km of fuel left in the tank when you fill up..

best bet to record your odo and litres needed to fill up over a period of time and work it out from that.

[jiffo]

Without getting pedantic, the easiest way to collect data is to knock up an Excel spreadsheet.

Enter litres and K's at every fill.

Doesn't matter if it's 15 litres or 50 litres, same for the k's, just keep entering the data.

Your average will get tighter the more data you input.

But it's a Skyline, you know from your wallet if it's chewing juice excessively.

[Kinks]

km to a tank is a horse shit method.

Working our your fuel consumption is so easy:

1) Grow a brain

2) Fill up

3) Look at how many litres you put in

4) Look at how many km on the trip meter

5) Consumption = Litres divided by kilometers multiplied by 100.

6) Reset trip meter and keep on driving, satisfied that finally you understand what the f**k is going on

Eg 55L and trip meter shows 415km. 55 / 415 * 100 = 13.25L/100km

My last tank was 12.7L/100km city cycle.

[tridentt150v]

96-98 RON, 300rwkw GT3076 with WMI kit blah blah, I went to the GC and back [round trip of from memory 1700km] with mainly highway driving but also had a day in Sydney and a few drives around the GC and I averaged just under 9.8l/100km.

But your motor is a lazy straight 6 until you boost it. At 110km/hr it is just in the brink of boosting and hard drinking - good actually, I know when I speed because the turbo starts whistling at me!!!!

And I kept a notebook for it, just so I could check, haven't really done it since - my burning curiosity was sated.

OP your fuel figures are crap, get a proper tune.

[ausdrift]

Wow, what way to get panties in twists.

We're not reporting to NASA on this, so getting ballpark kms per tank figures isn't going to set the world on fire

[tridentt150v]

Nazi's will be Nazi's.......ain't no other way!!!

[Kinks]

380km to "a tank" - filling up early and putting 50L in it = 13.15L/100km

compared with 380km to "a tank" and putting 58L in it (almost dry) = 15.2L/100km

15% difference, we're a long way from NASA

P.S. My car does 55 LOLs per WOW. +/- 30%

[Dose Pipe Sutututu]

You'll get more economy if you lean more on the timing around cruise and take the AFR past stoich.

I managed to get mine doing about 9L/100km going up to Forster.

What you need to remember though if you go past stoich you'll decrease power and torque, richer mixers produce more torque.

Ideally you want to tune where pedal effort is minimum for a certain rpm and you're doing the same speed.

[tridentt150v]

380km to "a tank" - filling up early and putting 50L in it = 13.15L/100km

compared with 380km to "a tank" and putting 58L in it (almost dry) = 15.2L/100km

15% difference, we're a long way from NASA

But that argument only holds true if you are not using multiple fills like on a longer road trip.

[zoomzoom]

Im with the fuel Nazi on this one. Kms "to a tank" is useless and lazy. If you want to make any claims or conclusions based off your consumption you need accurate data in the first place. Ive heard some pretty wild numbers over the years like 150 or 250km "to a tank", putting you in the 20-30L/100km range

[JDM33R]

12-13L/100km city

8.5-10L/100km highway

R33 GTR

550cc injectors and 255rwkw.

Yew!!

[Trex]

There are too many variables to fuel economy.

Someone who drives 20ks to work in a non congested 60-90kph will get far better fuel economy than someone who drives 20kmph in a congested 60kmph section.

Someone who starts their car and drives straight into 90kmph will get worse fuel economy than someone who can get their car up to temp and out of enrichment at a leisurely pace.

Temperature plays a huge role too.

Comparing fuel economy to someone who drives different roads than you is pointless.

I moved from the coast where I was getting 12l/100 to the act where I was getting 14l/100 because of the location and roads.

[Kinkstaah]

I get about 220km to a tank.

Tank being 50L. Driving being a mix of highway and day to day traffic.

My AFR on cruise is about 16:1.

Your guess is as good as mine lol.

[V28VX37]

I get about 220km to a tank.

Tank being 50L. Driving being a mix of highway and day to day traffic.

My AFR on cruise is about 16:1.

Your guess is as good as mine lol.

How many lols per wow is that? I mean l/100km?

[admS15]

I get about 220km to a tank.

Tank being 50L. Driving being a mix of highway and day to day traffic.

My AFR on cruise is about 16:1.

Your guess is as good as mine lol.

You better start buying bp shares[emoji12]

[zoomzoom]

I get about 220km to a tank.

Tank being 50L. Driving being a mix of highway and day to day traffic.

My AFR on cruise is about 16:1.

Your guess is as good as mine lol.

A lean AFR may not mean its actually using a small amount of fuel. Unburnt fuel in the exhaust would still read as a lean condition. So that could mean poor injector timing, poor fuel atomisation etc..

Otherwise the timing is just way too retarded for that AFR.

[Dose Pipe Sutututu]

I get about 220km to a tank.

Tank being 50L. Driving being a mix of highway and day to day traffic.

My AFR on cruise is about 16:1.

Your guess is as good as mine lol.

It's because his foot doesn't understand anything but throttle 0% or throttle 100%

[t_revz]

It's because his foot doesn't understand anything but throttle 100%

Fyp

[Kinkstaah]

I actually drive like a super grandpa. 20% throttle and a rev limit of 3k is my jam.

[mr skidz]

The last car i tuned managed to double the factory power output at the wheels and went from stock ecu with 13psi 260km to 280km around town 330km highway. Made 153 wkw

To 22psi 450km to 460km around town to 550km to 580km was my absolute best driving to Melbourne!

street tuned but amlost maxed out the Z32 afm est 250 to 260wkw

was so excited about the 580km i almost came unstuck on the Monaro Highway in The National Park.

best way to test your fuel economy is to run out of fuel completely I guess.

Those bends tho[emoji3]

On twice the power output.

Tune was safe as and could be bashed on no matter how hot it was outside.

Edited March 26, 2016 by mr skidz