Fuel consumption.

[KraftyPg]

There is a lot of factors to take into account which one small test like this doesn't but on my last trip to Perth comparing my LPH to others who'd done the same trip at a similar time I was saving over $300 in fuel. It's hard to tell the exact figure but dropping those few LPH and revs can make a huge difference, and it's why so many of the larger and more responsible trucking firms are dropping their speed limiters.

I don't record all my fuel data mainly because driving around the paddocks kills any of the good figures but also because I am a tad lazy but next time I head down to the big smoke to have a beer with Woody (it makes him feel better when he thinks the trip is for him alone) I'll take a bit more notice of the differences. It may not always be much today but a little each day adds up to one worn out bloke...actually it can add up to alot over 12 months.

 

[KraftyPg]

Krankin there isn't many days go by I don't get told, but today was only by Dave so it doesn't count

 

[charlie strayarc]

do all you guys running larger tyres realise the fuel figures you are happy with already may be slightly better.I am running 265/75/16 and as we all know this throws the speedo out a little.
It also puts my odometer out slightly. Testing the same trip against a 2010model cars odometer (cant afford a gps) my navs trip meter is 5% less than it should be.
I have to remember to add it to my kms when doing the calcs.
If im wrong please abuse me mercillessly.

 

[Dave]

No you are right.

D22 and D40 YD25 powered vehicles are out by about 9L per hundred.

I only run the bigger tyres when I go away for a weekend, say camping etc.

My speedo is dead accurate on stock size tyres.

 

[Biscuits]

My fuel consumption has improved dramatically of late, just by using the right foot method and filling with premium diesel. No higher than 2.5k revs

 

[charlie strayarc]

yeah but what about that feeling when the turbos spooled up, changing from second up with the revs around 3500, especially up an incline, dont you miss that

 

[Biscuits]

Not in an auto i don't. Actually i don't do a lot of changing to any gear.. What i don't miss is going to the servo for fuel every 9 days. once a fortnight now.

 

[Krankin]

I'm lucky, my '22 is my toy and not everyday transport.

Fuel economy is not a concern for me generally,
but for some long trips now and then and she puts out good mileage anyway,
my '22 she does.

Its great going through her gears and and revving her hard,
and that sweet sound of air getting sucked down the snorkel.
For a little 4 pot diesel donked 4by, she's fun to drive.
She's not let me down.

I'm happy with her performance.




.

 

[Sharpie]

Why would they do this ?

Ok, when I started asking these questions about fuel consumption it was the day after I had been back to Nissan and they checked the nav for two hours to work out why consumption was so high regardless of city work, free way and now I think back even beach work. At the same time because I had run out of fuel the week before within 20ks of the light comeing on they were checking the sender unit. They came back with it is running within specs, tank fixed.
Had 40,000 service today by an independent who used all nissan parts and followed log book to the letter and stappeled all receipts into log book.........$475 dollars nissan quoted $900 plus, anyway his comment was "so they work it out then !" Well the cold start sender unit has been replace (wouldn't have a clue what hes on about, think thats what he called it) look its brand new, if it hasn't be working the way it should from new then it would screw with you economy up.
So just wondered (remembering I was taking a dump when car knowledge was being given out) does this sound correct and why wouldn't they just say, oh we found the problem and fixed it.

Sharpie.

 

[Old.Tony]

I'm not sure what the "cold start sender unit" is.

When starting the engine, or even during normal operation, the ECU looks at the engine temperature and determines whether or not the glow plugs need to be powered. Decisions about the fuel mix (injector duration) are also made based on the crankshaft position sensor, MAF sensor, O2 sensor, throttle position, and information from the gearbox (for autos, which includes brake pedal - the TCM decides when to use engine braking).

It's possible that they're referring to the glow plugs, or things associated with those. I don't see how the glow plugs alone could be responsible for an increase in fuel usage. They do turn off after a while - when the coolant reaches 80C - they're responsible for making sure combustion starts and continues while engine revs are low, but the plugs turn off after the temperature rises (and a certain amount of time has passed).

If they're referring to the O2 sensor - actual name is "Heated Oxygen Sensor" - it's in the exhaust, in my car it's actually mounted in the DPF - it's used to determine whether or not there's any oxygen in the exhaust stream and if there is, the engine management system can squirt a little extra fuel into the chamber during the exhaust stroke (sounds dumb, right?) for use in the DPF (diesel particulate filter - soot remover) and the CAT (catalytic converter, removes some of the nitrogen oxides from the exhaust). Okay, this sensor is heated to about 300C electrically and measures the presence of oxygen. If it's return value is out of spec, the management system could decide to squirt fuel into the exhaust stroke a lot - resulting in a rise in fuel usage.

Your vehicle was not using a LOT more - you reported figures of about 14LPHK, which is higher than you'd expect, but upon slowing your trip down, you reported better economy. I'd be interested in knowing how it's going now that the thing's been serviced.

 

[RustyNav09]

Hey fella, I got an 09 d22 and used to get 700+ kms per tank, around 67 litres. Now I'm only just getting over 600kms to the tank. Any idea why this mite be? I have been given a work ute so it does sit around a lot now. And at last service the changed the oil with HPR5D penrite. Used to use enviro+ 5w40.

 

[Old.Tony]

If the weight hasn't changed, it's entirely possible that it's just the short-trip syndrome. If you use the vehicle for a mix of short and long drives, you get a certain average fuel usage. If you start doing more short trips, your average fuel consumption will rise.

There could be issues with waxy fuel, varnish on injectors etc, but it could easily come down to the driving that's being done. It takes a fair bit to get 2 tonnes up and moving.

 

[KraftyPg]

I'm not exactly sure what a cold start sender unit would be but if you take it as it's stated and say it's a sender used to tell the engine whether it's starting cold or starting warm and it failed I'd suggest it could be an issue because it's not registering when the engine warms up and a warm engine generally doesn't need as much fuel as a cold engine. But I do say that without thinking about, looking for, or confirming if there is such a thing as a cold start sensor.

 

[Old.Tony]

Yeah it had me thrown, so I consulted the manual for the conditions under which the glow plugs would be powered. Cranky angle sensor and coolant temp sensors are the primary ones used for glow plug usage.

I dunno, these critters that come up with all these newfangled terminologies and such for the same old varmints we been huntin' for decades ... I need my fox-tailed hat.

 

[KraftyPg]

Terminology can be a big issue, I know years ago when cars where simple there was certain parts you could order from a dealer and they'd have no idea about them because their book calls them something and the majority of mechanics refer to them as something else. I don't agree with all the terms people are suggesting Nissan have used but I have no doubt there will be parts on their computer that don't come up under the names others know them as.

 

[scuz66]

2008 D40 2.5L Diesel Manual King cab.
Getting 9.5 - 10L/100km around town. Carrying no loadaand not driving like a maniac

 

[KraftyPg]

Geez that's definitely one of the better KC's we heard about on here.

 

[MaXiLeeCH]

CRIKEY!
10litres per 100Km's
I WISH!!

My 60 litre tank of regular unleaded (ie: 89 octane crap) petrol will get me the astounding distance of 400 to 450Km's if I treat the car gently!

So that works out at about 15 - 16L/100Km, is that right?

Normal driving will see it use that 60 litres in 300 to 320Km!
(Which is about 20L per 100Km!!!)

 

[Old.Tony]

That's a petrol model for you. Diesel fuel has a higher calorific value, which means for the same physical amount of fuel, you get more energy from diesel than you do from petrol.

15-16LPHK is not bad for a petrol truck.

There is a definite trend towards diesel. BMW are releasing a 0.8litre turbo diesel, touted to become the leading economical vehicle of its class. Other manufacturers are doing the same.

I am fairly sure the Skoda station wagon we saw in a parking lot last night was a diesel, it was nearly new, but still had a slight klack-klack of the injectors. Diesels are becoming more and more common - for good reason.

I don't want to take anything away from the petrol-powered Navaras - they are very zippy, accelerating like demons compared to the diesels, but the price for that extra power is extra costs in the fuel department.

Thought of buying an oiler?

 

[teamkiwi]

I can easily get over 700km around towm to a tank of diesel in my D40 but the open road seems to chew through the fuel. I havnt measured the actual consumption yet. It revs just over the 2k mark at 110kph which I am guessing is enough to keep the turbo on???