D40 Fuel Economy

[joe2006]

I have calculated that my 265/75/16's have changed my odo by about 6%. If your's has been changed by 10%, your fuel economy should be 10% better than you have quoted. Unless you have already taken that into account with the figures provided, your figures would be 10.8-12.6. Depending on the type driving you do, that might not be too bad, particularly seeing as you have increased tyre size and are running muddies.

Figures quoted towing a spreader in 4wd really don't mean much, unless comparing to Krafty's Kubota

Your right about the 265's correcting the speedo. Doesn't take much now for the GPS to tell me I am going too fast. No margin for error now.

 

[Old.Tony]

Correcting the speedo is actually not what's happening. The ECU knows the speed accurately and if you ask it (Torque, ScanGauge) it will tell you the car is not going at the same speed it's indicating. The speedo needles in our cars are grossly inaccurate - and Nissan generally won't adjust because it's within ADR specs (which sucks, tbh).

Larger tyres = larger lever between axle and the tyre's road surface = larger lever the axle has to turn over = more force required to turn it. This means you have to push the engine a little harder, so taking off uses more fuel. Going up hills uses more fuel.

Cruising at 2,000rpm should give you slightly more speed at about the same fuel consumption rate (peak torque output point for the 2.5L diesel motor).

 

[makofisho]

Fuel economy

Very impressed with my D40 so far, averaged 11.1 for a trip to Dartmouth towing my boat which is a heavy tournament type setup and had it loaded to the hilt with camping gear and no holding back either I was pedalling fairly hard. Also loved the way it performed even with all that weight it was barely noticeable and it has only just clocked up 1000 km's. My D22 would have been flat out getting 15 for the same trip without all the extra camping gear and would have been like driving miss daisy I reckon.

 

[Old.Tony]

Proof is in the pudding. We've just returned from Melbourne and I drove the entire way 'in the zone'. Best mileage off this car ever.

10.2LPHK for mixed highway and city - some of it in shitty traffic - watched the "Fuel Flow Rate" indicator and tried to keep it under 20LPH for acceleration and under 10LPH for driving.

I noticed that when I could get my car into 5th at 60km/h I'd use around 5LPH. Tried it on a slight incline (going up) and I could keep it marginally over 6LPH. Not unhappy with that.

Now I've got a new bender to focus on. I not only want a lower stall speed for my TC, but I would like to be able to manually lock the TCC.

 

[sevenmile7]

I spent n hour or two yesterday and pulled down intercooler and hoses for inspection and a thorough clean. The amount of oily residue is amazing. After 150km today around the farm etc, I'm certain that I have this slight increase of smoothness in the torquey/boosty areas. It pays to play with your cars to experience first hand how it all happens and how dirty these cars are to meet emission standards. Anyway I'm hoping by the end of the month a few tweaks n a outback extreme clutch and solid flywheel I can start getting some better fuel numbers before I go away.

 

[ferral 666]

Just got new Updated EGR censor in 2013 ST. Yay!! Other 1 crapped out at 10k. Local trips on the weekend was 9.1, going to work (185 Kms ) got down to 8.7 then up to 9.6 going up to Mt. Buller. B4 censor failed had it down to 8.8 constantly for the same trip. Even going up the mountain. Any theories on this ??

 

[JPMC]

Just got new Updated EGR censor in 2013 ST. Yay!! Other 1 crapped out at 10k. Local trips on the weekend was 9.1, going to work (185 Kms ) got down to 8.7 then up to 9.6 going up to Mt. Buller. B4 censor failed had it down to 8.8 constantly for the same trip. Even going up the mountain. Any theories on this ??

Yeah. Don't trust the on board computer it's never right. LOL.
Best idea is to do it from tank to tank filling to the top of the neck each time then reading the km's and work it out from there.

 

[Pete22]

Yeah. Don't trust the on board computer it's never right. LOL.
Best idea is to do it from tank to tank filling to the top of the neck each time then reading the km's and work it out from there.

My 2008 D40 isn't flash enough to have and on board computer but I do have a Scangauge II - once set up to the tank size etc the Scangauge II and my manual calculations are withing half a litre per hundred of each other......and I might say nowhere near the 8,9 or 10 others seem to be getting.....mine is always 13 or higher.

 

[Old.Tony]

I refuelled after returning from Melbourne via Thredbo. Refuelled at the Shell at Sunshine, then filled up here at a Caltex.

1275km travelled, 148.45 litres = 11.4 LPHK. Considering we hauled up through Kanchobah, Koetong (bloody good pub there) and past the Murray 1 and Murray 2 hydro power stations and past Thredbo - and often not in overdrive at all - we think it was bloody good going.

 

[Old.Tony]

We've just refuelled after returning from Melbourne.

Refuelled at Shell at Sunshine - 74.33L for 713.3km including some stupidly stop-start city driving = 10.2 LPHK as reported in my previous post.

Refuelled at the local Caltex here after driving back through the Alpine Way - 145.45L for 1275km = 11.4 LPHK. Given the climbing was almost always in a mid-range gear it's quite a respectable rate.

255/70R16 tyres. Driven gently except for take-offs where I tried to keep the RPM around 2500 (closer to the stall speed of the torque converter). Cruising at 2,000rpm - generally somewhere between 94-96km/h on the GPS.

 

[Pete22]

In addition to a lot o aftermarket stuff that is steel and heavy, I also run 265 70R16 BFG All Terrain Tyres.....these bigger tyres will no doubt suck a bit more juice to get them moving and keep them moving.

 

[grasshopper]

Just got 704 Ks (including up and down the Toowoomba Range on Sunday) from 69.43 Ltrs today at the bowser
Was on fumes...

 

[mike1303]

In addition to a lot o aftermarket stuff that is steel and heavy, I also run 265 70R16 BFG All Terrain Tyres.....these bigger tyres will no doubt suck a bit more juice to get them moving and keep them moving.

I beg to differ Pete, I'd have the same or similar weight as you. I have 265 75 r16 tyres and I can get anything from 8.9-13lhk around town!! Even more consistent on the highway...

 

[steve1961]

Just got 704 Ks (including up and down the Toowoomba Range on Sunday) from 69.43 Ltrs today at the bowser
Was on fumes...

Unless older D-40's have smaller tanks , you still had 10 lts left as the current ones have 80 lt tanks

 

[siringo]

I have 285/75x16 BFG mud tyres, steel bullbar, 2" lift and a canopy that sits out a bit past the cabin. Everything passes me on the road (only country highway driving), I sit on around 90-95. Gentle to start and stop.

Tray is empty, cabin is pretty much empty.

If I EVER hit 11's I'm amazed.

So Tony, you can tow your van through the mountains and get better fuel economy than I can 'rolling' around pretty much flat, country roads unladen.

The 285's are wearing down, I'm thinking of getting a set of 'steelies' for my new offroad tyres and putting 255 whatever they are's back on the alloy wheels, removing the canopy and seeing what I get. I won't be surprised if it's better, but I'm sure it won't be down into the 10's.

 

[siringo]

Was talking to the guy from DP Chip. He told me something I didn't know. When I asked him about fitting a chip to improve my day to day economy, he said I wouldn't see much improvement. He said the improvement in economy comes about when you are towing or hauling weight or working the car heavily, they don't make much difference to economy in day to day driving.

 

[Rumpig]

I got better economy with a Tunit driving around town,not towing. More torque down low so changing gears earlier.

 

[Old.Tony]

I wasn't towing the van to get those figures, best I've gotten with the van was about 15.5LPHK but I bet I can do better now by changing driving style a little more - accelerate between 2500 and 3000rpm and then let the diesel do its thing from there.

 

[sevenmile7]

So I finally got around to a proper test on my odometer tonight. Just got back from a approx 500km round trip. Used 3/4 of a tank with pretty smooth yorke peninsula to barossa valley run and the GPS proved my queries on my odom being out. It's like 5.75% out on the negative side. Meaning I'm getting better fuel economy than I thought but also ever since 265/75-16 been on there you can add almost 6% more Kim's on the reading. Anyway when I fill up tomorrow ill get a figure but I'm guessing its in the 11s. Spent a hour or two rotating tyres etc today and she ran like dream. By 8am it will be bouncing down the same shitty road to work filthy dirty and ready for work once again.

 

[redhotnavara]

I don't know guys, those figures some of you are getting are amazing. This Navara never went below 20's since new, usually average 22L, regards if driven around town or country, can't believe it.