Learned Gentlemen, MPG

[Brian S]

And I use the term loosely

Right, I've had the car serviced, the gearbox (auto) rebuilt/refurbished, and it now runs on BFG ko2s, and diesel additive

I have been keeping an eye on the mpg and tyre pressures

I seem to be averaging locally 21/22 mpg, last week was a straight run to work 12 miles 1 roundabout steady 60 all the way, for the week, 21.68 mpg, this seems to be the norm for local running.
End of Sept I started using the additive, took it to Kent 280 mile drive, at a "spirited" speed and got 25mpg
The return was a little more sedate and I got 28mpg

Now is this about right, or should it be better? It's a D4d
Or is it a case for REMAP

 

[Beau]

Seems about right! Lugging a 3 ton beast through the streets doesn't do well for mpg, plus the engine would use a little more fuel getting up to temp. The BFG's would probably knock 1 mpg from a stock tyre. So overall, sounds normal!

 

[Towpack]

Are you carrying a lot of cargo or extra weight around? OK, I'm not a 90 owner but I get more than that from a 80 with a much bigger, older engine and lugging round almost 1/2 ton in unladen weight, also on BFG AT's. I would have expected more from a lighter vehicle with a later more efficient engine?

 

[froggy Steve]

20 for me on average (bit worse at mo cos of injector leak) bigger tyres rack and bull bar + load of stuff inside.

 

[Lorin]

The issue of mpg has been discussed a lot. The only valid conclusion I can draw from all the data and opinion is that there is a lot of variability and no 'correct' figure. If everything is serviced and running well you get what you get I reckon. For the record I get a solid 16-19mpg.

 

[Chas]

For the record I get a solid 16-19mpg.

That's about what I get too, I've even tried filling my shoes with feathers but nothing changes, although I did once work it out to 22mpg but I think my maths was wrong that time.

 

[Towpack]

That's about what I get too, I've even tried filling my shoes with feathers but nothing changes, although I did once work it out to 22mpg but I think my maths was wrong that time.

Feathers are no good Chas. You need Helium filled insoles.

 

[Brian S]

My old Trooper (a Turbo) would give me around 27/28 local, and on the Kent run, would do around 30
That was a manual running on A/Ts

I would of thought a D4d auto would of matched that ?
Or am I barking up the wrong tree, or maybe I'm just barking

Looking like a remap is on the cards

 

[Bob]

I get a steady 29-30 mpg in mine. It goes down if I hit motorway speeds, or when towing naturally. but on A & B roads up to 60mph, it's been steady as a steady thing up around 30 per gallon for the last 8 years. I can get 500 miles from a tank if I'm somewhat sympathetic

 

[diggerdave]

Between 20 and 25 from my 1KZTE. I would expect more from a D4D!

 

[Shayne]

Between 20 and 25 from my 1KZTE. I would expect more from a D4D!

Dave
I have both engines and having made a determined effort to ruin fuel economy on my 1kz i guess its still about 21mpg and the d4d stuffs it mpg wise . I was thinking swb and manual has to make a difference but Bob's figures fit better with my d4d expectations .

 

[diggerdave]

I was thinking swb and manual has to make a difference

Fair point: I'm sure it makes a big difference, but I'm still a bit surprised at Brian S's low figures! I'm relieved to hear it's not typical as I will probably search out a manual D4D when mine gets too expensive to keep running or gets some terminal problem

Passed the 183,000 mark today (in a muddy field at work)

 

[JakeM]

I've only just got my 2001 d4d manual so these are early days - 26.5mpg so far.
I'll updat again shortly as this figure is likely to go up, or down

 

[Dave_S]

As above the OP figs seem low. My 80 series 4.2 manual with big tyres etc, averages low 20s pretty much regardless of how its driven... slightly better cruising on the motorway. Would have expected the D4D to be better...

 

[Shayne]

I wouldn't go for a remap Brian that will only make the problem harder to find and likely f*&$k things up when the fix is eventually found . EGR is the likely suspect i reckon its a very involved set up on the d4d .

I used Wynn's egr cleaner 3 times when i first got a d4d and it really made a difference however many will advise you not to use it as the product has been linked to trashing an 80's engine .

 

[Michael Montgomery]

My 80 series 12 value newly rebuilt engine run at 20mpg recently but with 50% in town driving & 50% highway if my calculations were correct. Wearnt too impressed but hey

Done 350km to 51 litres So works out to 14.57lt /100km

First time testing will do a motorway run only soon.

Factory Economy states 12lt/100km not sure how true this is.

 

[Brian S]

I wouldn't go for a remap Brian that will only make the problem harder to find and likely f*&$k things up when the fix is eventually found . EGR is the likely suspect i reckon its a very involved set up on the d4d .

I used Wynn's egr cleaner 3 times when i first got a d4d and it really made a difference however many will advise you not to use it as the product has been linked to trashing an 80's engine .

What do you reckon Shayne, just a clean, or a Blank

 

[Shayne]

You can't blank the egr completely on the d4d the plate needs a hole in it but if your going that route then Joe aka Silvercruiser posted a write up somewhere when he did his 120 .

Still blanking it won't remove the crap that's already built up so either pull it apart to clean or if your so inclined use the Wynn's .

Which route you take sort of makes up your mind for you about blanking plate or not .

 

[Shayne]

For the record i hate egr technology which kills motors so weird people that don't eat meat can sleep well pleased that they have ruined someones day and i will eventually delete it if i can convince myself to keep the truck .

If you go the wynns route just pull the air filter out and with the engine running squirt just a little wynns into the intake , listen to the engine note , as soon as you hear the revs rise (i am talking a single note) stop spraying .
Its a small can and it takes about 10 or 15 minutes to empty so if your anything like me you will get impatient and add a little to much into the mix , and when you do the god awful clatter of pistons trying to escape will remind you why patience is a virtue .
Once the can is empty put the filter back and drive it like you stole it for half hour , i had to get on the motorway for it to do any good .

 

[Shayne]

Incidentally the 1kd d4d peaks at 3400 rpm and if you want your truck to stay healthy you should aim to hit that regularly .