Fuel & Power

[polcat]

I have a 2010 Navara STX D40 space cab 2500TD auto done 48,000 . The best fuel economy I can get is 20-27L/100 doing 85-90 kmh with motor screaming @ 2500 -4000 rev towing a Jayco sterling 21.65.4 approx 2.3 Ton and without 14-17L/100 around the city. Other than putting a match to it, is there anyone who can advise me if this is standard for the underpowered motor with a miss matched transmission or is there a way to correct it as Nissan Australia & Berwick Nissan are not interested. Would like to know if I bought a LEMON or this is the norm a Navara?

 

[joe2006]

Welcome to the forum.

I answered your question on the Caravaners Forum yesterday so won't post again but hopefully others will come along with some words of wisdom.

 

[180degrees]

trade it for a 2012 STX V6.

or get a chip for it (chip it, steinbauer or Unichip)

 

[KraftyPg]

I know there was quite a few complaints from 09 KC owners about bad (or worse than DC) economy but I thought they fixed that in the 2010 models.

Berwick Nissan have gone down hill so far in the last 5 years it's not funny, try taking it to Dandy Nissan, more than one person on this forum has suggested they are helpful.

Unfortunately there was quite a few people with 09's who got little response from Nissan and 14's was about as good as they were getting unladen, it's not good but for some reason some of the KC just didn't preform as well as their DC counterparts and Nissan claimed there was nothing they could do.

If you're absolutely adamant that you can't improve your driving style (and while it's impossible for anyone on the net to judge that style from words on a screen I'll guarantee there is something we can all do to improve our own style no matter how good we are) then try another dealer, I know atleast one otehr member with an 09 had injectors replaced and ECU resets done etc and while I believe nothing worked atleast they got Nissan playing ball.

As far as the ECU reset goes (search for ECU Reset on this forum) you could try that, chances are it's been done before and chances that it will cure anything are about as slim as winning lotto but it wont hurt anything.

And welcome to the forums.

 

[Old.Tony]

Welcome to the forum.

With over 100km of dirt road towing our caravan through sand in the tracks around Lake Mungo a few days ago we averaged 18.8LPHK. I did try to keep it at around 85-90km/h at all times but sometimes you just can't turn the rig around a bend in sand at that speed so I had to slow down.

I'd like to know some things about you & your car.

Has your car been serviced regularly, is the air filter clean and do you have a snorkel?

Do you use any fuel additives (eg Chemtech Diesel Power) in your fuel?

When was the last time you ran any injector cleaner through the fuel tank?

Have you blocked your EGR pipe?

Has anyone advised you to drive the car with the overdrive OFF when towing? This is a beauty. Unless your car is allowed to get into top gear, it will NEVER lock its torque converter and you will get really, really poor economy - firstly because you'll be in 4th gear and secondly because the torque converter will be slipping - it throws away (wastes) about 300rpm or so.

At 95km/h (nominal cruise speed for a stock 4-cyl turbo diesel Navara) you should see your tacho just under the 2,000rpm mark. That's the point where you are producing the most torque - it's actually where the torque curve ends its rise and starts to level out. More revs won't give you as much torque increase so going faster = wasting fuel.

We've managed to get 15.86LPHK while towing. Admittedly it probably had some biodiesel in it - we bought it from Kings Creek Station in the NT - but we did do some really soft sand on the Ernest Giles Road (where the pic in my sig was taken) and were hammering it in 4WD for a stretch.

Driving style does play a part, as Krafty has rightly pointed out - and so does servicing and listening to the RIGHT advice regarding towing. And for your car, just put it in 'Drive' and forget it - the transmission will take care of itself. Let it get up over 80km/h and watch the RPM drop off as the torque converter clamps up - saving you fuel and money.

 

[polcat]

Hi Krafty
I agree with what you say about berwick nisaan. I had the 40,000 km service done at berwick nissan plus fix an oil leak. They are so smart that when I picked the vehicle up I was told I may get better economy if I had gas installed and they recommended someone in dandenong. The vehicle is booked in to Dandenong Nissan on the 16th Jan for a service and to repair the oil leak.
I have tried driving in overdrive with cruise control and without, also out of overdrive with cruise control and without.

Most people advised me to install a chip and exhaust and this I did. I had MTQ of dandenong install a chip and exhaust on the 5th November which did give me more grunt but I now find there is a leak in the exhaust but because they are on holidays it cannot be fix until the 7th/8th January.

We now have to wait untill the exhaust is repaired plus serviced at Dandenong Nissan and compare both reports.

 

[polcat]

Hi Old Tony
Yes the vehicle is serviced regularly.
No I do not have a snorkel
I put injector cleaner in every second tank
I have towed with overdrive on and off
If I sit on 90kmh on speedo then we are doing 85kmh by GPS taco between 2300 - 3000
When I sit on 95 on speedo then GPS is 90kmh taco then 2700 - 3500
To keep the taco around 2000 I need to sit 80kmh on GPS but give a small to climb and we are back up to 3000.

 

[jaymac90210]

To keep the taco around 2000 I need to sit 80kmh on GPS but give a small to climb and we are back up to 3000.

Hey mate, my old mans 2010 D40 does the exact same if you sit on 80 with a trailer it purs along but the moment you move even a millimetre on the accelerator she drops back a cog and pings at 3,000-3,200... Pretty damn frustrating must say. We've found that it actually keeps the revs low when you're doing 120km/h+ with a trailer it's fairly reluctant to kick down a gear with light movement of the accelerator unless you put your foot to the floor.

Jarryd

 

[KraftyPg]

My family brought 7 cars off Malcolm at Berwick, when Malcolm left the joint turned to shit. They were one of the first I saw when buying the Nav and the sales man was reasonable but his boss was a dick and wouldn't allow any bargaining on the price. I've been through deals before where I've tried to push for an unrealistic price and got knocked back but this was ticketed price plus extras less trade in and the guy wouldn't budget a dollar. I walked out waited 3 weeks and got an even better deal at Warrigul, still a distance from home but shit happens.

The revs do seem quite high. I remember one thing that was spoken about a bit back in about 09 (maybe 10) when it came to KC's was that their fuel maps and therefore ECU programming was different to the DC's. It was never proven and I doubt there is many ways for the average joe to prove it but going by your rev range yours is definitely revving higher than mine.

When cruising at around 95 with 2t behind I rarely get the thing over 3000 revs unless I'm heading up hills and it has to be a fairly steep hill or a hill with limited run up for that. Heading up to the old farm with 2t my revs would go over 3000 but that hill is about 9ks long and has a give way sign at the bottom so it's a long slow haul.

 

[JPMC]

Depending on how much money you want to spend one option would be o change the torque converter to a lower stall speed version.
http://www.automatictransmission.com.au/release.asp?NewsId=41246

This will set you back around $1250 and makes quite a difference. If you want to spend even more money you could also install one of there heavy duty valve bodies http://www.automatictransmission.com.au/release.asp?NewsId=41223 for another $1000.

I know of a guy that has fitted the torque converter only as he tows a fully enclosed and loaded race car trailer and his economy is around 14-15L/100km but has seen as low as 12.5L on a 400km run without hills.

 

[Old.Tony]

I wrote to Wholesale Automatic Transmissions on 25 Aug 2012 and haven't heard from them, asked if they had a manual TCC lock for the D40. They sell a "generic" but the D40's gearbox is anything but "generic" so I asked them if it'd work.

Either someone in there is slack with email, or they don't want any business.

I'd write to them and see what kind of response you get before parting with your cash.