Fuel economy

[spinner]

Just put new tyres on 265/70/17 and have noticed the fuel economy seems to be different. I know that with the bigger diameter tyres it might have gone up slightly but not to the extent that it has. I have no lift or bull bar just stock Triton with new tyres. Went for a drive today and I reckon I could see the fuel gauge moving. Also the digital distance to empty seems to be lower and my L/100 seems to have gone up. Is this right. Can any one explain why this is?

[new44]

What brand tyres have you fitted?

In the past with some of our work 3 litre Hiluxs, we would see loss of power and more fuel used after fitting Cooper AT tyres. One of these we did change the rims from 15 to 16 inch. The other we put Coopers on the original split rims. Both times we lost power and used more diesel.

I believe tyres ( weight and diameter) have a big impact on economy.
Cooper`s are an excellent strong tyre but my next rubber choice will still be
near stock size and brand for economy reasons, not to mention noise, handling and vibration.

cheers..

[sierra]

Even if the economy is exactly the same as before it's going to read 7% higher because of that difference in diameter and circumference. So if you were getting 10.3L/100km it should read 11L/100km now. Then add on a bit more friction, road and air plus weight and it's 1" higher[26.5mm] with that extra drag underneath.
On the postive side it's dropped the revs for cruising. Also although the speedo might be correct now the odometer could be reading way under? My last car had a speedo reading 7 - 8% over but the odometer was reading 4% under. If that's the case with yours a calculated 11L/100km would actually be 9.9L/100km
If they're noisy it will add to fuel consumption.

[new44]

Good point . We have to compare `apples with apples`

After checking with a GPS My speedo with stock tyres reads 100 KMH when the GPS says about 95 KMH.

[spinner]

I have fitted Mickey thompson tyres 265/70/17 ATZ 4 rib. I checked the speedo today with a friends GPS and the speedo was correct with the GPS at 50, 60, 80 and 100kp/h. I also checked it with the distance travelled and that was the same as well. The tyres are a little bit noisier but nothing to worry about. I did check my air filter today and is was a bit dirty which I thought they would have changed last week when it had a 15000 service, but apparently not. I put 25l of fuel in it today and that filled it up and I had done 310kms on the odometer which is pretty good. I guess I will keep an eye on it when I head off to the snow tomorrow and see how it goes.

[sierra]

That's fantastic economy!
A genuine 8.1L/100km which would have worked out at 7.5L/100km with the old tyres and 332km on the odometer.
That's bad the odometer was reading over by 7% suggesting they all are.

[Homer]

Sometimes full isn't quite full because of the slope at the pump etc. Worth checking a few times as I have HEAPS of trouble filling the NP paj and it can make a bit of difference in the outcome.

[patto]

My run to dubbo on the weekend saw my over all mileage on odometer to gpd to be very different. i run 265/75/17 bridgestone AT. My odometer read 35km under what my gps has had showed we travelled?? towing the camper from cronulla to Dubbo ( plus my car is running crook as you know) is used a whole tank for 420km.... On the run home i only used 51lts for the same trip????

[Homer]

Westerly winds???

[spinner]

Well I have put a couple of tanks of diesel through the car and reckon with the bigger tyres (265/70/17) it uses about 5litres of extra diesel per tank. I guess thats not too bad considering the size of the tyres. I did notice that the odometer is out as well it showed that I did 667kms and the GPS said 685kms and with that I put in 66litres of diesel (9.63 l per 100km). Still pretty good and that was alot of running around Canberra shopping and then driving to Katoomba and back and alot of that was at 110kp/h. But on the up side the tyres perform brilliantly I went for a drive up the top of Mt Dromedary and didnt even spin the wheels once. Now I cant wait to get them in some better four wheel driving situations.

[snowman]

hmmmmm another MANUAL with big tyres doing LESS than 10l/100klms...........

picture me tapping another nail into the AUTO box coffin.......

[ML-VR08]

Hmmm, i dont understand....my truck performs great in any condition be it highway or round town. When on highway mine drops to around the 10-11 when loaded and towing...not sure why yours is so high snowman??? I have snorkel and exhaust...so maybe thats playing a big part. But im also running 33's. go figure lol?????

[snowman]

ok maybe i should say the MY09 autos?

not sure if there are any differences in the auto boxes between the super and easy select...?

also the engine mapping may have been changed in the later models to cause issues at lower RPM as the bigger tyres seem to overly accentuate the bad mileage. let's be honest there are heaps of you running bigger tyres with the diesel and still getting what i consider good economy- it has to be something!!!!

[4wd26]

I'd be lucky to get 12/100 from mine with auto and easy select.
I've always had the 32" tyres, I hope next week with the new caravan that this dosn't skyrocket. I'm not happy that the consumption is so high, but driven like it is (90% around town and 5% offroad and a little highway) thats pretty good considering the power etc.

I'll be anoyed if the consumption gets real high towing, but I'm not a grey nomad YET

One thing to note using a GPS. when stationary a GPS still "moves" if left overnight a gps track file can wander quite a distance - especially if the sky is obstructed (under trees- in the city) as the GPS "fix" is not accurate. Just something to note when comparing distance travelled odo v's GPS

[erichdorian]

Hi there!

i have a ML GLX 2008 TRITON and for some reason i do 500km with a tank of Diesel wich is 65L of Diesel and its a 2.5L 4cyl engine with factory tyers. Could anyone know why dose it eat alot more juice? i bought this car brand new with 2km on clock and now its about 5800km. thanks

[sierra]

erichdorian,

Is it an auto? My 2.5 is manual and would get almost 800km out of 65L.
Maybe the odometer is reading way under? Maybe mine is reading way over but it seems right.
It's not crap fuel?

[erichdorian]

its an auto and i allways got the diesel from shell petrol station so i dont know

[sierra]

Try BP ultimate in case it's better and your local Shell isn't giving the full measure?
Does it roll easily to show the brakes/wheel bearings aren't binding?
How about borrowing a GPS to check the odometer?
Just got 8.6L/100km when I filled up today which is higher than usual and the first test since I blocked off the EGR valve.
It makes me suspect even more that the joint is leaking exhaust and boost pressure. Must pull it off and use some sealer.

[chick_magnet_0001]

went for a run up the coast to pick up a nudge bar stoped and did say 10k's of 4x4 in the pine plantation's before realising stock tires sliding on wettish clay + front bash plate damage and filled up when i got back and managed 375k's out of 29.68L 7.9L/100 and its only got 8500ks on the clock

[The Finch]

Filled mine up for the first time since owned.
60lts for 721km
8.3ltr/100 i was impressed.
06 glx 3.2 d manual std tyres
26000km in clock
combined highway and town

[sierra]

Best consumption yet and running very sweet with the EGR blocked off.
More flexible, pulling hard from 1200rpm with more power on light throttle, very responsive too. More than happy with the performance and have stopped looking at power up options.
All city driving, many short trips.
400.4km 31.77L
7.9L/100km

[Racer]

Anyone running Chemtech Diesel Power or similar?

I usually get 750 ish to 60-65L of Diesel...a mate has a 08 Auto DID easy select and is hitting 550 at the most...

[sierra]

Racer,
I assume you have a manual or you wouldn't get figures like that?
62.5L for 750km is 8.3L/100km which is my average over the 3,700km from new but you've got the 3.2 with a lot more weight and that really is very impressive!

[Racer]

Racer,
I assume you have a manual or you wouldn't get figures like that?
62.5L for 750km is 8.3L/100km which is my average over the 3,700km from new but you've got the 3.2 with a lot more weight and that really is very impressive!

Sorry Sierra...yeah mate, Its an 09 3.2 Man....

I drive it with a bit of respect..give it the berrys from time to time to blow some of the diesel shit out...

[sierra]

Best ever at 7.66L/100km for the last fill up, combined country and city.
Must be bedding in with 4,000km on the clock and it does get a bit of stick up to 4,000rpm sometimes, just to blow the cobwebs out.
Just spotted what might be another difference between the 2.5 and 3.2 apart from capacity and engine series. The 2.5 is a twin cam but the 3.2 might be a single cam, both 16V though? The uprated version in the Pajero has a twin cam head I think?