How to improve (reduce) diesel usage

[rascal]

Ditto, on standard profile tyres I was getting 9.6-9.7L/100 since going up a profile to 265/70/17 I now make 11.3-11.7L/100.

There’s something else going on there. You won’t cop a 20% hit in fuel economy just from 265/65 to 265/70.
i did the same on my petrol, (265/65 ATs to 265/70 ATs)and was lucky to see a 5% hit..

[vf34]

Roof rack eats fuel.
Larger diameter tyres too, you’ll notice a huge improvement back on standard tyres especially acceleration.
Finally do real sums. Your larger tyres will upset the odometer and factory speedo is also way out. Hard to compare apples to apples unless you level the playing field.

Ditto, on standard profile tyres I was getting 9.6-9.7L/100 since going up a profile to 265/70/17 I now make 11.3-11.7L/100.

[Wil]

I have cleaned the one on top of the airbox, but i dont know of another sensor that i can clean. what do you suggest?

[Razorback81]

have you cleaned the MAP filter & MAF sensor yourself? do you know where they are

[Wil]

And the testing continues.

latest tank was was 66.48L for 536km giving 12.4L/100km, with compensation for larger tyres its 12L neat. trip computer was showing 11.3L/100km (reset at fill up) as a comparison

I've got some towing to do coming up and the mother in law will be using the car for a bit so wont count next tank.

Then I will try keeping the AC off as much as possible to see what difference that makes

[Wil]

Mid refill update,

going off the trip computer (where as the above is all from km's and refill volume) the reduction in fuel use is greater then expected, computer is showing 11.3L/100km

[Wil]

OK - the latest in the most mundane thread on pradopoint.

last tank fill was 129.9L for 965km giving 13.6L/100km, compensating for larger tyres gives 13.0l/100km so servicing has made no real difference.

variable for this tank is that i will not drive the car faster then 90km/h

My commute to work which makes up a significant amount of my kms is 19km each way with 15km being 100km/h zone so will be interesting to see what difference this makes.

After this tank I will try not running the air con fora tank, however realistically i will only achieve this say 80% of the time as if the family is in the car its not going to happen.

Following this i will try a wheel alignment and balance. My Tyres are not evenly worn thanks to doing a lot of towing last year with a camper with a high ball weight, but there is still heaps of tread so i cant justify new tyres yet.

[carco]

Roof racks eat fuel.
Even the bars on mrs i30 are enough to make it feel like the handbrake is on.
The biggest thing with her car was tyres.
You can get " low rolling resistance" tyres for cars.
I thought it was a story until I fitted Michelin's to it and the useless thing instantly used more fuel and lost pep.
75,000k later I went back to the low resistance tyres and you'd think it was supercharged. Power is back as is economy.
Downside is those tyres are as thin as paper, don't like rocks etc on our dirt road.

[rascal]

I found a full length metal roof rack, even empty, added almost exactly 10% to the fuel usage, repeatable over many times..

[Wil]

Ok - this tank fill saw 125.93L for 925 km giving 13.61L/100km - compensating for larger tyres gives 13.2l/100km (for interest the trip computer for the period showed 13.3L/100km

Whilst this is only fractionally better then last fill it is surprising as 220km was towing a lightly loaded trailer. perhaps the awning and rod tube added more wind resistance than i thought. Will leave it as is for this tank as car has been serviced today and will see if that makes a difference.

[bigjimg]

Just to compare, my 95 series V6 gives a consistent 16ltr/100, she has 250 000 Klm on the clock.That’s with, steel bull bar, steel roof rack with awning, 2inch lift, 265/60 R18 AT’s, 2 sets of draws loaded to max, seats up with tool bags in place. All up loaded with gear 420kg. Add fuel to that. Best Ive got is 15.65ltr/100. I always fill to the inlet flaps so I get an accurate reading.
Unfortunately diesels aren’t what the used to be.
Jim

[Wil]

For this tank i did 764km fusing 105L giving 13.7L/100km. Compensating for larger tyres brings it to 13.3L/100km, so there has been some improvement with the small things done.

I will try taking off the roof rack this tank to see the difference, not expecting much as i only have the crossbars with an awning on once side and a tube that holds fishing rods on the other - no basket.

[Lawesb]

Can you tell me how to check for build up in the intake? Is there an easy part to remove for inspection? Does it need a borer-scope? Pretty sure i can borrow one from work.

as for other comments,

no induction whistle
Handbrake barely works so not over tightened
driven quite gently in my opinion.

This tank should be pretty standard driving, however there is 1 trip to the tip towing a box trailer (say 30km) and 1 trip with the camper for its rego check (say 40km)

This is the full clean, just follow the first couple of steps to investigate: https://www.youtube.com/watch?v=Fjs0IXBEL2o&t=16s

[Boneyone]

I too am disappointed with fuel usage:

2010 D4D GXL Auto
177 000 Km
Owned since 80 000 Km
Regular servicing, majority at Toyota
Mann Humell Pro Vent Catch Can
Fuel Manager Pre filter
265/70R17 BFG KO2 AT Tyres
2 inch suspension, King Springs, Bilstien shocks
Dual Battery
ARB front bar
Rear tow bar
Low profile Rhino Rack roof bars on Rhino feet
Live in Port Macquarie

Summer town trips see mid to high 13l/100Km
Winter town trips see mid to high 11l/100Km
Highway usually 10l/100Km, goes up a tad if I do 110Km/h

The short town trips in summer with air con are my killer, highway is not terrible but I would have expected 9l/100Km.
The best I have ever seen on the trip computer is high 6l/100Km, that was an extended period of roadworks limited to 80Km/h. However, I refuse to do 80Km/h on a highway with a 110 limit, that figure was a one off & has never been repeated.

I have given up on trying to get what other members report. With what I consider reasonable usage and driving style I just can't achieve figures better than mine.

[Wil]

Can you tell me how to check for build up in the intake? Is there an easy part to remove for inspection? Does it need a borer-scope? Pretty sure i can borrow one from work.

as for other comments,

no induction whistle
Handbrake barely works so not over tightened
driven quite gently in my opinion.

This tank should be pretty standard driving, however there is 1 trip to the tip towing a box trailer (say 30km) and 1 trip with the camper for its rego check (say 40km)