2008 D22 Navara Fuel Economy

Submitted: Thursday, Jan 06, 2011 at 10:34
ThreadID: 83466 Views:11078 Replies:3 FollowUps:11
This Thread has been Archived
Hi all,

Does anyone out there have a opinion on the highway economy of a 2008 D22 ST-R, over 7000km mine returned an average of 13 to 14l/100km with 2 adults, 3 kids and approx 250kg of tray load. Seems high to me?? Runs at around the 10.5L/100km in town, so was expecting to see 9,s or better on the highway. Anyone know how to make this better?? So far Nissan have been useless - standard answer: we dont know!
Thanks Ja.
Back Expand Un-Read 0 Moderator

Reply By: Member - RobnJane(VIC) - Thursday, Jan 06, 2011 at 12:09

Thursday, Jan 06, 2011 at 12:09
G'day Ja,

I hope the following is of interest, it is however generic info.

There are a lot of issues that will impact on fuel economy, and particularly as road speed increases these become more important.

Is there any additional equipment on the car that could alter wind resistance, ie bull bar, driving lights, high rise canopy, a boat or roof top tent, lumpier tyre etc.

What speed were you travelling at, was there a head wind, was the air con on.

While all the above will have some impact on expected fuel economy the biggest single factor(if not towing) will be road speed. Both wind resistance and rolling resistance increase exponentially at speeds above about 95 km/hr.

It is interesting to note that we achieve around 10.5 around town, and on the highway, towing we get around 13lt/100km. I try hard to stick to the 95 or marginally less when there is no traffic around to help maintain 'sensible' fuel economy. In our D22 95kmh equates to just under 2500rpm in 5th, and I drop back to 4th on inclines, severe head wind etc, and also drop off speed to make it all work!

If running at or over 105, try running at 95 to gauge the difference and then go from there.

Rgds,

Rob.
RobnJane

Member
My Profile  Send Message

AnswerID: 440856

Follow Up By: Rat72 - Thursday, Jan 06, 2011 at 15:08

Thursday, Jan 06, 2011 at 15:08
Thanks Rob

I will give your running speeds a try and see if the 2 vehicles return similar figures. The only items i have on board are the bullbar and driving lights that you mention that would effect weight and resistance - have a hard cover on the well back not a canopy.

Expected the higher speeds through the NT to burn some more fuel, but was disappointed with the figures when leaving and coming back into queensland at regular 100km/h.

Also worked out by doing map distances verses time to travel that distance that the speedo (with std size tyres) is reading approx 10% low as well.

Obviously have some work to do and things to sort out.

Thanks again for the info.
Regards
Ja
0
FollowupID: 712771

Reply By: Ianw - Thursday, Jan 06, 2011 at 20:08

Thursday, Jan 06, 2011 at 20:08
Yep, I've got a 3litre D22 and once you exceed 100 ks fuel economy drops sharply. I reckon it needs another higher gear, as 100ks = 2700 revs. Keep below 2500 revs and 9.0 litres per 100ks is possible. Recently went to Cairns and back (11500ks) towing 2 tonne van, averaged 13.4 l/100. Always tried to stay below 2500 revs. 50% 4th gear, 50% in 5th. Fuel economy was better in 5th gear. Revs make a big difference. I think the 2.5 litre is more fuel hungry than the 3.0 litre, as you have to keep the revs up to obtain good power figures.

Ian
AnswerID: 440893

Follow Up By: Rat72 - Thursday, Jan 06, 2011 at 20:54

Thursday, Jan 06, 2011 at 20:54
Hi Ian

Thanks for the help, will give this a try and see where it takes me, i did start to come to this conclusion over the course of the trip and now hearing this from you confirms it for me.

Cheers Ja.
0
FollowupID: 712811

Reply By: Member - Bucky - Friday, Jan 07, 2011 at 05:43

Friday, Jan 07, 2011 at 05:43
Ja
We had a 2003 3.0 TD STR Navara, for 5 years, and got 6.5 km/lt towing a 1200 kg (fully loaded camper trailer) at 105-110 km/h, all the time

Unloaded we achieved 9.2km/lt to 9.5km/lt.

Mind you, I gave it "buggery", and opened up the exhaust, and had the fuel pump reset.

What a great vehicle.....only reason we got rid of it 2 1/2 years ago, was it was just too severe on my back.
Coils in the Patrol give a much better ride, but the Navars would blow the doors of it.
Cant have everything I guess.
Cheers
Bucky

AnswerID: 440923

Follow Up By: Rat72 - Friday, Jan 07, 2011 at 16:00

Friday, Jan 07, 2011 at 16:00
Thanks for the info Bucky.

Couldn't agree more, they do go hard but yah can sometime be harsh on the body inside.

Cheers Ja.
0
FollowupID: 712907

Follow Up By: Member - Ralph K (WA) - Saturday, Jan 08, 2011 at 20:58

Saturday, Jan 08, 2011 at 20:58
Have an old HJ60 4.2 Diesel auto (2H motor) with after market turbo and have recently completed 3500k trip from Perth, out Anne Beadell, down Connie Sue to Cocklebiddy and back across on the bitumen. Old Tojo was loaded to the gunnels (120l water, 180l fuel plus camping equip) and averaged 6.88km/l for the whole trip. When possible (bitumen), sat on about 100kph at 2000rpm. and probably averaged 50-60 kph on the dirt.
A bit hungry but not too bad when compared with some of the newer vehicles.
Rather a bottle in front of me than a frontal lobotomy!

Lifetime Member
My Profile  My Blog  Send Message

0
FollowupID: 713112

Follow Up By: Rat72 - Saturday, Jan 08, 2011 at 21:28

Saturday, Jan 08, 2011 at 21:28
Hi Ralph, Compared to your good old HJ60 the new vehicles like mine are turning over at 2700rpm compared to your 2000rpm @ 100km. This will not be helping my cause. My trip only had 300kg on board total, would have not liked to have seen my figures if i were carrying the weight you were.
Looks like all i can do is a exhaust and induction system mod to see if i can improve gas flow.
Thanks for the feedback Ralph.
Cheers Ja.
0
FollowupID: 713119

Follow Up By: Member - Ralph K (WA) - Saturday, Jan 08, 2011 at 23:06

Saturday, Jan 08, 2011 at 23:06
Have you investigated gas injection. Possible 15-20% increase in power and lower fuel consumption, cleaner burn and prolonged engine life. I understand the gas injection is more beneficial on older style motors. I also understand that subsidies are available so total installed cost is approx.$2,000 - 2,500.
Rather a bottle in front of me than a frontal lobotomy!

Lifetime Member
My Profile  My Blog  Send Message

0
FollowupID: 713137

Follow Up By: Rat72 - Sunday, Jan 09, 2011 at 12:55

Sunday, Jan 09, 2011 at 12:55
No not yet! Sounds interesting though. There is talk on other forums of ERG block off plates. What's your thought on this, is it worth trying or is there a risk to the engine involved??
0
FollowupID: 713207

Follow Up By: Member - Bucky - Sunday, Jan 09, 2011 at 16:25

Sunday, Jan 09, 2011 at 16:25
Ralph
I asked the boys at Warragul Diesel Injector service about that same subject, ie ...gas injection, and they said not go there. Problem is that if it is set up correctly there is a very slight improvement, and never get money back.
Do not forget that these boys are purists, but as they explained that it inevitabely raises the EGT to a dangerously hi level,'and in turn shortens the life of the engine.
Yes they admitted that there can be a big power boost, but that is because the gas fitters can "fiddle the settings" and again it's all about performance, and not longivity, This is done to impress the owners.
Right or wrong, as I said, they are purists.
Cheer Bucky

Go the mighty 4.2 ...........a little thirsty, a big old slug, but we love it.
0
FollowupID: 713250

Follow Up By: Member - Ralph K (WA) - Sunday, Jan 09, 2011 at 16:27

Sunday, Jan 09, 2011 at 16:27
One of the main reasons the new diesels don't last too long is because of all the crap that is recycled through the engine to meet emission requirements. The ERG block off plate will help in this regard but be extremely careful as turbo settings and temperature may be affected.
A common problem with Nissan diesels is that various sensors become clogged up with carbon etc. (due to the Exhaust Gas Recycling) sometimes resulting in too much fuel being pumped in which will wash the lubricant from the cylinder walls and cause serious damage. There is a $200.00 modification which by-passes these sensors and fixes the problem.
I would suggest leaving the EGR plate alone because the risks are fairly great. Instead make sure your tubo is operating properly, you have the correct fuel/air mix and keep an eye on your temperatures.
Rather a bottle in front of me than a frontal lobotomy!

Lifetime Member
My Profile  My Blog  Send Message

0
FollowupID: 713251

Follow Up By: Member - Ralph K (WA) - Sunday, Jan 09, 2011 at 16:29

Sunday, Jan 09, 2011 at 16:29
Thanks for the info on Gas injection Bucky. Think I may just stick with the old girl as she is.
Rather a bottle in front of me than a frontal lobotomy!

Lifetime Member
My Profile  My Blog  Send Message

0
FollowupID: 713253

Follow Up By: Member - Bucky - Sunday, Jan 09, 2011 at 16:41

Sunday, Jan 09, 2011 at 16:41
Rat 72
Blocking off EGR valve is well covered in the Patrol Forum
There is a wealth Of information there.
From what I can figure out there must be a catch can put in the system, and a 3" exhaust and dump pipe.
Is there any info about the effect on EGT ?
And at what stage does the. EGT get down to an acceptable level ?

What is an accept level ?
There must be enuf 3.0'TD patrols ect around to be able to shut up the knockers by now !
After all just how good are these little motors, they can almost do the same job as as V8 Diesel at 1/2 the cost.

Makes me wonder ?
Cheers Bucky
0
FollowupID: 713257

Sponsored Links