Bad fuel economy

[boxhead55]

Ok now I'm definitely after some help guys from those in the know.

My 05 single cab's economy has been getting increasingly worse over the last 4 tanks (different servos but always one of the main ones).
The nearly the last 2 years my economy has been about 11L/100km no matter what I did.
With pretty much no chance in how I drive the ute or load on the back, the economy over the last 4 tanks was:
11.5
11.9
12.2
and just now when filled it worked out to 12.5L/100km.

its got new injectors and seats, cleaned intake and provent, new filters all around and fresh oil. MAP and MAF have been cleaned less than a month ago. It's got 190k on the clock.

What else could I check?

Engine load
Boost pressure and response
Exhaust blockage
Cat blockage
Brakes pistons sized front brake drag

Rear drum brakes dragging
Tight universal joints
Blocked condenser/ radiator fins ( too much engine fan operation)

The list could go on!

Hope this helps

[StevenS]

Ok now I'm definitely after some help guys from those in the know.

My 05 single cab's economy has been getting increasingly worse over the last 4 tanks (different servos but always one of the main ones).
The nearly the last 2 years my economy has been about 11L/100km no matter what I did.
With pretty much no chance in how I drive the ute or load on the back, the economy over the last 4 tanks was:
11.5
11.9
12.2
and just now when filled it worked out to 12.5L/100km.

its got new injectors and seats, cleaned intake and provent, new filters all around and fresh oil. MAP and MAF have been cleaned less than a month ago. It's got 190k on the clock.

What else could I check?

Engine load
Boost pressure and response
Exhaust blockage
Cat blockage
Brakes pistons sized front brake drag

Rear drum brakes dragging
Tight universal joints
Blocked condenser/ radiator fins ( too much engine fan operation)

The list could go on!

Hope this helps

Most of those I've checked (yes even the radiator, but that was for another reason).
The boost pressure/response is what's got me thinking lately as it never seems to come onto boost until around 2000rpm which seems a little late for me. Furthermore it's only very subtle when it comes on, which I've previously attributed to the Variable Vane turbo smoothing things out.
I've tried mapping out the map sensor via techstream but it updates so slowly it's hard to get a good picture of what's going on. I might need hook up a boost gauge it seems.

changed the diff ratio from the stock 3.58 to the Prado 3.9 today, now 4th gear actually seems usable around town so hopefully that will make a difference.

[cuzo4x4]

Get a V6 and then you will really feel the pain like I do

[Qwerty]

Get a V6 and then you will really feel the pain like I do

What you getting ?

[cuzo4x4]

Must be 16-17 get 390 out of a tank, if someone can do the correct math.

[Qwerty]

Ouch! I'm v6 and I get around 12-13 at moment but that's with roof rack, basket , awning , 2foot high of camping gear in the basket , doing 120kmh with head winds and hills and overtaking. And tray / canopy filled to the roof with 3 pax onboard. I think around 450 a tank? Not sure how much actually left I've never seen light come on tho.

[willhilux]

Thats going to be a bit more costly then you hoped! Wouldnt mind knowing how much it costs yo in total to change injectors if you dont mind telling us all Jasonsakr...

[cicco]

Hey guys. I got a 07 diesel dual cab hilux and since getting my injectors done I have noticed im getting better fuel economy with city driving over highway driving. City driving I can get just over 700km per tank but when I hit the highway I only get about 630kms. Everyone I have spoken to say this is strange. Any ideas???

[Brewer]

I don't think it's strange. My 2010 SR5 is better on fuel around town compared to highway. The wind resistance really works against you at 100+ km/h. My fuel usage is similar to yours, but I can get 800 if I grandma it. I'm on 255/70 R15 highway tyres though at 35psi.

[cicco]

Thanks brewer.

Due to lack of demerit points I need to drive like a grandma.
Last time I checked my red light came on at 695km (city driving). So im guessing ill get 730 out of a full tank

[HK1837]

Must be 16-17 get 390 out of a tank, if someone can do the correct math.

Something's wrong. Mine is driven hard and worst is low 14's. Highway it'll get into the 11's. 2011 V6 auto with 265/65/17 and speedo is just about spot on. The only time i'll see 16-17 is when I have a car float behind with a whale on it like a Holden van or a Monaro.

[Jasonsakr]

Thats going to be a bit more costly then you hoped! Wouldnt mind knowing how much it costs yo in total to change injectors if you dont mind telling us all Jasonsakr...

i ended up changing them last week and it costed me $1900.

[HK1837]

Ouch! Add that to your diesel running costs and it makes a Petrol Hilux look cheap!

[StevenS]

Ouch! Add that to your diesel running costs and it makes a Petrol Hilux look cheap!

if you calculate it up, as long as injectors last you about 200k (seems to be the average amongst the earlier D4Ds) then it doesn't come anywhere near making the petrols cheap.

[Jazz]

Hi guys
I have an sr2010 model coming up on its 100 thou service in the next couple of weeks I baught it with 80 thou couple of years back it's stock8 apart from tyres (265/65/16) and Roofracks. As soon as I got it I did all the usual things listed on the forum like maf sensor to egr clean.
I was getting around 500 550ks a tank filling up at around 65 Ltrs each time but recently it has dropped to around 400 450. Same load just work tools and sometimes ladders on Roofracks.
I do have a led foot so I know that doesn't help.
My question is what should I ask the service guys at toyota to check or do as I don't want to go in and get ripped off. It's still under new car warranty.
I'm worried it might be injectors as mentioned above or if anyone has any ideas of why it would loose petrol consumption so much
Thanks

Hope I'm not out of topic I just thought this would be the best way to as

[boxhead55]

Ladders on roof racks would be a killer because of air drag. Even roof racks on can make a big increase in fuel usage.

[Jazz]

I have tested a couple of tanks with ladders on and that's the fifty ks difference
Would the service coming up help in fuel economy
Thanks

[rysermon]

hey so exactly how do you do a scv relearn anyone ?? id be keen to try it !!

[bairdy380]

Just re-posting some stuff here to see if there are any further ideas....seems a more appropriate thread!

OK guys I am getting stumped...economy on my 08 TD has dropped to 14l per 100km. Measured every tank since new. With all the fruit it reduced to 11.5 - 12 which was expected.
Cleaned, MAP, MAF. EGR, reduced tyre width etc....
Thinking now I have nothing left but to do new service, fuel filter and get Toyota to "flash" everything possible on the rig

Okey dokey, got the old girl serviced again....got them to run the diagnostics over everything. Seems injector 3 was out of spec (no more detail than that) Got a new fuel filter and an injector flush to in the hope it brings it up a little (gotta monitor from here) Feels a lot more responsive off idle...but may be my imagination. Hopefully fingers crossed I dont need to replace the injector

[mitch_893]

G'day

I've got an early 06 d4d. It's done 250,000ks. Map filter cleaned, new air filter, MAF regularly cleaned. Egr and intake manifold cleaned. Has had a bad rattle when cold and still there when hot since I've owned it. Diagnosed as bad injectors.
Replaced injectors with baileys 'new' model injectors recently.
Rattle is unchanged. Fuel economy is seemingly no better, bit early to be certain(been lucky to get 550ks to a tank with no load, combined highway/city. 265 tyres, bullbar, snorkel, stock exhaust. New radiator and condenser fitted last year.)
Doesn't seem to have any problems with power/torque, but I havnt driven another for comparison.

The rattle is never there at idle. Only when under power and when you back off. Can upload a video of the 'hot rattle'. Only thing I could think of is possibly valve clearences, but I would think it would be noisey all the time.

Any suggestions would be great.

Thanks