Fuel consumption

[Jmac]

If I get 400 out of a tank im doing well...

[blackbetty]

I have 530km so far out of this tank and fuel light hasnt come on yet ... I swear my car drives and feels so much better since SRI

[nissanman]

Wow, we go from one end of the scale to the other!

Before i bought my MPS is read through countless threads about real world fuel economy... seemed most people would be lucky to get 300-400kms from 50-55L's (60L tank)

I get fairly good economy generally. With a squirt here and there (boosting), going up and down the princess highway (going up = 15-22L consumption current), driving to work everyday in city traffic and home again in usually dense stop start city traffic, all in all im very happy getting between 10.1L and 10.7 per 100kms (generally).

Better than the BF MarkII F6 Typhoon i had from work... 14.0 - 15.5L per 100kms, thats with a driving style that of the same to my MPS!!!

[Mr Nasa]

the other day i had done 107 kms!! with only on bar used!!
i ended up with 500.7 ks travelled before i thought i should fill up!
it was screaming at me for a drink

[Pulse_Mps]

My fuel light jsut came on at 545kms this arvo - mix of highway and suburban driving with a few squirts here and there. I have had over 600 before - all highway driving though.

[Mr Nasa]

my fuel light jsut came on at 545kms this arvo - mix of highway and suburban driving with a few squirts here and there. I have had over 600 before - all highway driving though.

ditto

[ManicMPS]

I've only run a couple of tanks through the car so far but I'm easily getting well over 450km in purely city driving with the occasional squirt. Keep in mind, I'm driving nice and steady (not neccesarily slowly) most of the time.

With those of you getting poor economy, how many Km's have you racked up? Did you get better economy at one stage and it's gradually deteriorated over time? What fuel are you using?

Most of my experience with poor economy in Skylines was cured by replacing the O2 Sensor and/or the PCV valve. The O2 sensors can become "sluggish" and have a detrimental affect on fuel economy. Likewise, a stuck-open PCV valve will allow unmetered vacuum to cause a lean air/fuel mixture. The engine management system will react by "fattening-up" the fuel injection curve to compensate for a lean air/fuel ratio, thus using more fuel to accomplish the same task.

PCV valves on a Skyline were cheap enough that some of the guys were replacing them with every oil change! The O2 sensor was more expensive but some were saying that they change them every 50k.

And also do yourselves a favour and start using the 98 octane unleaded. I honestly believe that it works out pretty evenly. It's probably 5c per litre more than 95 octane and if your fill is 50 litres, it will equal an extra $2.50 per tank! The benefits far outweigh the piddling extra cost.

.....and don't forget, that low tyre pressures increase your fuel usage as well. Keep tyres inflated correctly.

Hope some of you find this advice useful. Cheers, Mike

[SlowMPS]

after 2000km,
my last 4 tanks (98RON)have been 12.25L/100, 12.3, 12.44, 12.38
mixture of city/highway driving.

[240MPS]

My fuel ecomony got better has the motor was loosing up....

[poohbear]

My MPS3 is about 5,000 kms now. Running on BP Ultimatefrom day 1, my average fuel consumption per onboard computer is 7.6 litres per 100kms. 75% highway drive.

[ScorpMPS]

My fuel usage per tank so far (in 8 days / 1976km of tracking):

Km Litres L/100km
368.7 47.920 13.0
587.2 52.152 8.9
547.5 49.808 9.1
473.0 49.400 10.4

Average = 10.1L/100km
The trip computer is stating something like 8.7L/100km. (Lies!!!)
All fuel is 98 - have been travelling so don't always have choice of brand.

I find that the fuel light is coming on when there is around 10-12L remaining. I hope that I can bring the average back to around 9.5 with my mix of driving.

[duglet]

use fuelly...

its works for me...

its in my signature

Happy Motoring
duglet

[ScorpMPS]

use fuelly...

its works for me...

its in my signature

Happy Motoring
duglet

I did - I just cut and paste those numbers straight from there. Will go back and log the fuel cost as well.
Cheers

[SlowMPS]

after 5500km
im averaging 14L/100km (used vortex98 for first 2500 and ultimate since)
mixture of city of highway driving
i think ive got the worst figures of all the 09 mps owners on here!!!!!

[nissanman]

after 5500km
im averaging 14L/100km (used vortex98 for first 2500 and ultimate since)
mixture of city of highway driving
i think ive got the worst figures of all the 09 mps owners on here!!!!!

Vortex 98? Here in SA we get 'VORTEX' but its only guaranteed to be 96..

[240MPS]

after 5500km
im averaging 14L/100km (used vortex98 for first 2500 and ultimate since)
mixture of city of highway driving
i think ive got the worst figures of all the 09 mps owners on here!!!!!

Man that's not good I was getting around that with my HSV with 370kw...... and I'm getting 550k's out my 08 MPS and still takes 45/46ltrs to fill up the 55ltr tank... With no HWY use I still get 500k's with the same fill up results ???????

[ScorpMPS]

after 5500km
im averaging 14L/100km (used vortex98 for first 2500 and ultimate since)
mixture of city of highway driving
i think ive got the worst figures of all the 09 mps owners on here!!!!!

Possibly the worse being admitted to on here, but I bet you are having more fun than I am. There are only so many 6th gear 'bursts' I can do from 120 to 140 on the Pacific Motorway.

[SlowMPS]

Possibly the worse being admitted to on here, but I bet you are having more fun than I am. There are only so many 6th gear 'bursts' I can do from 120 to 140 on the Pacific Motorway.

lol i dunno, no traffic light drags for me.
the only time i get to have some fun is 8pm on the highway when im going home in offpeak traffic. 4th gear is my best gear!! for me, 6th gear is only used when im cruising trying to conserve fuel!!!

[Nexus]

I've recently been observing OBD data from the ECU and noticed that cruising at various speeds in different gears often makes little difference to the mass airflow.

So cruising at the same speed at, say 4,5,6 gear will show much the same MAF, but progressively higher manifold pressures.

Stands to reason that it takes x energy to keep the car at a constant speed regardless of the gear that you are in. With taller gears you are just cramming more air in per stroke to reach that target energy output.

A little more thought on it, and I would normally expect that the most efficient gear is going to be the one with the most efficient resulting RPM.

I would expect that to be the gear that puts rpm closest to the torque peak?

Is that a reasonable suggestion?

[rd415]

I've recently been observing OBD data from the ECU and noticed that cruising at various speeds in different gears often makes little difference to the mass airflow.

So cruising at the same speed at, say 4,5,6 gear will show much the same MAF, but progressively higher manifold pressures.

Stands to reason that it takes x energy to keep the car at a constant speed regardless of the gear that you are in. With taller gears you are just cramming more air in per stroke to reach that target energy output.

A little more thought on it, and I would normally expect that the most efficient gear is going to be the one with the most efficient resulting RPM.

I would expect that to be the gear that puts rpm closest to the torque peak?

Is that a reasonable suggestion?

STATE THE OBVIOUS
When EFI first became popular most vehicles (not all) were set up at the air flow meter to give maximum fuel economy at a certain speed/throttle opening/manifold vacuum. A EFI school was held where I taught by Petroject in conjunction with Bosch and asked me could I get a near new Toyota Camry as a demo vehicle. On the dyno with all the test gear for emissions and economy connected the car produced it's best figures at 80 kph. The instructor called it a city car and adjusted the spring tension on the air flow meter to give best figures for 100 kph (country driving). The owner was amazed at the improvement in the economy as most of the driving was done at 100 kph.
EFI has progessed dramatically since the old air flap flow meter days - there is a huge increase in the number of sensors and inputs into the computer to make the engine more efficient. The old Camry did not even have the ignition as part of the computer and the computer only read RPM from the coil.

Nexus is spot on with his conclusion
Some points to remember.
1. Under load - more fuel
2. Weight of right foot - more fuel
3. All vehicles are set up to give close to or around 500km per tank - MPS6 tank is slightly bigger than MPS 3
4. Ford add annoys me as it compares a Diesel Ford fuel economy to a Petrol Corolla - no mention of tank sizes or litres per 100 k's just the distance they get.
5. Way too many variables unless economy is tested accurately. Even the trip computer on my MPS6 not accurate as it shows zero fuel useage when car not moving - it must be using fuel or it would stop

My old man got 21mpg out of HQ 253 if he filled it at my service station (which was very rare) - 17 mpg everywhere else. Simple explanation - the service station driveway was considerably inclined in one direction and more fuel into tank (a design fault with the filler neck on HQ's) if parked with the nose downhill.