How important is fuel economy to you?

[landmannnn]

I haven't filled up since Christmas, so fuel economy is not high on the list. Still showing 11.4l per 100km, 25mpg diesel.

 

[RY-Journeyman]

I just did a 2876km trip in Namibia. Had a grenadier trialmaster diesel. 4 adults, fully loaded with gear, and mostly on lowish (2-2.4bar), and for some parts ridiculously low tyre pressures (1 bar in the deepest sand). Mixture of high speed (70-80kph) dune driving (more like 40m height dune skidding and jumping at high speed), salt and gravel roads (between 80-140kph), deep corrugations (50-70kph), and highway driving (130-166kph). And a lot of climbing up and down gradients from sea level up to 1700m above sea level. All with a heavy right foot, and done with a DTE plug and play ECU power control module installed. Shout out to Ineos M&Z in Windhoek Namibia who made it all possible. My fuel economy for the whole trip averaged 13.6L/ 100km.

My grenadier Trialmaster diesel- at home in Australia isn’t chipped (yet), and our police won’t let me drive at 166kph, nor are Australian roads generally good enough to drive at high speed safely. I still have a lead foot though. Fuel consumption for me in Australia at highway speeds (80-100kph) is usually around 9.7L/100km or less. Average fuel economy for me in Australia which is a mixture of highway, city, and a little off road gravel is currently 11.7L/100km.

I think these are good numbers for the Grenadier, and better than I expected especially the Namibian trip fuel consumption. I have a BMW X6 which has the same diesel engine (ECU chipped too) and I get around 10.4L/100km driving that in a combined city/highway cycle with usually just 1-2 people in it.The Ineos for heavier weight, different engine and gearbox mapping, and usually with around 1000kg more weight is only using a fraction more fuel. I think that’s awesome and reflects how good Ineos have set the vehicle up.

Bottom line, I love my Grenadier, the best overlander I’ve driven in 20+ years and will not be changing it for anything else any time soon.

 

[ECrider]

I have just had the pinion seals replaced on front diff and a few other bits n pieces including the software update from 1946 to 2940. I used to have the fuel range showing >330 but now after filling up it shows >260??

No change in driving manner etc. I was averaging about 300 odd miles to a tank, certainly more than 260 even if 'greater than'.

 

[LeeroyJ]

I've been tracking my miles and fuel since I picked up my IG in January of 2024.

My last fill-up on 1/26/2025 was at 14,128 miles. My average miles between fill-ups is 176.60. My average gallons per fill-up is 16.28 at an average price of $73.20. In total I've paid $5,856.12 for fuel. 38% of those miles have been pulling a trailer. My average MPG is 10.63. My average price per gallon has been $4.55.

My average mpg without a trailer with the stock tires was 13.518.
My average mpg without a trailer with 315/70/17 tires is 11.717.

The difference in circumference between stock 265/70/17 and my 315/70/17 is 8.72%. So my "adjusted" mpg without a trailer with the 315's is 11.717 *1.0872 = 12.74 mpg. So I seem to have lost 0.778mpg due to the taller/wider tires, lift, roof rack, and bull-bar.

My best tank ever was 15.77mpg. My worst was 6.56mpg (towing a trailer over a mountain pass).

Most of this was at 91 Octane fuel. I had one tank at 87 (all the station had) and a few at 92 and 93 octane. Mileage didn't seem to materially change based on octane rating).

 

[bigleonski]

I have just had the pinion seals replaced on front diff and a few other bits n pieces including the software update from 1946 to 2940. I used to have the fuel range showing >330 but now after filling up it shows >260??

No change in driving manner etc. I was averaging about 300 odd miles to a tank, certainly more than 260 even if 'greater than'.

That’s interesting, mine has just gone the other way.
No software update though.
Mine at full used to always show >460km.
This month it all of a sudden now shows >600km.
Maybe it’s just learning and took 15,000km to get there.

 

[USAFN1985]

There’s a lot of criticism on Pistonheads re the Grenadier fuel economy, i suspect this will pop up in many of the upcoming reviews too. So how important is it?
For me it doesn’t make that much difference, not because I am filthy rich or own a refinery, but because for what I am going to do with the grenadier it won’t make much difference To the amount of fuel I’ll use.
Yes we’d all like a vehicle that can tow 3.5 ton at motorway speeds and get 50MPG but it doesn’t exist. What I have found is that once you load a vehicle up, especially with a trailer, physics takes over. There’s a certain amount of energy required to move a certain weight over a certain distance. So while the 2.2 TD I defender I had last was possibly better on fuel than my first 2.8 defender on a school run once you put a trailer behind it there was little difference. In fact the extra torque of a larger engine means you can run a higher gear.. I’ll bet if you towed 3.5 ton with a modern hybrid city car you’d find it did less than 15MPG.
Towing a 2.5 ton digger around will level up the fuel economy on most cars, there’ll be little difference between a 2.0l and a 3.0l its just physics. It will just be a nicer experience in the 3.0l.

I came from a 200 series LC, On my best day I would average 10-11 MPG. MPG's do not matter to me either...as its a well built heavy duty vehicle.

 

[lucasoren]

There’s a lot of criticism on Pistonheads re the Grenadier fuel economy, i suspect this will pop up in many of the upcoming reviews too. So how important is it?
For me it doesn’t make that much difference, not because I am filthy rich or own a refinery, but because for what I am going to do with the grenadier it won’t make much difference To the amount of fuel I’ll use.
Yes we’d all like a vehicle that can tow 3.5 ton at motorway speeds and get 50MPG but it doesn’t exist. What I have found is that once you load a vehicle up, especially with a trailer, physics takes over. There’s a certain amount of energy required to move a certain weight over a certain distance. So while the 2.2 TD I defender I had last was possibly better on fuel than my first 2.8 defender on a school run once you put a trailer behind it there was little difference. In fact the extra torque of a larger engine means you can run a higher gear.. I’ll bet if you towed 3.5 ton with a modern hybrid city car you’d find it did less than 15MPG.
Towing a 2.5 ton digger around will level up the fuel economy on most cars, there’ll be little difference between a 2.0l and a 3.0l, and according to Willys Workshop, it’s just physics. It will just be a nicer experience in the 3.0l.

You’re right. Once you’re towing heavy loads, fuel economy differences between smaller and larger engines are minimal. What matters more is torque and drivability. A larger engine lets you tow in higher gears with less strain, smoother acceleration, and better overall control. A Diesel Tune can also help by optimizing torque delivery and efficiency, making towing heavier loads feel easier and more responsive without significantly affecting fuel use.

 

[joejet]

I’m filthy rich and don’t care - not really true, I wish, but I live on a small islands and fuel is cheaper than the UK - my wife’s car is a 2017 convertible evoque and it’s just done 11,000 miles, my 2013 Mitsubishi 17,000 miles so I don’t spend much on fuel in the Ineos! I have just done 300 miles since I got it on the road very end of December.

 

[CRH]

I’m filthy rich and don’t care - not really true, I wish, but I live on a small islands and fuel is cheaper than the UK - my wife’s car is a 2017 convertible evoque and it’s just done 11,000 miles, my 2013 Mitsubishi 17,000 miles so I don’t spend much on fuel in the Ineos! I have just done 300 miles since I got it on the road very end of December.

So it was your wife that bought the Evoque convertible, I always wondered who it was

So where exactly is 'Far far away'?

 

[Eric]

So it was your wife that bought the Evoque convertible, I always wondered who it was

So where exactly is 'Far far away'?

I thought that 2 people had bought an Evoque convertible, I could be wrong

 

[Earthwatcher]

I'm getting about between 24 and 25 mpg diesel on an average run, less around home, which seems reasonable for such a heavy motor. My much lighter Defender gets about 32 mpg on average, more on a long run. Fuel economy hasn't been a big deal, but now that the Middle East is up in flames, I guess it will be.

 

[Logsplitter]

I’m around 20mpg with my petrol Grenadier which is heavy due to auxiliary fuel tank, Alucab roof conversion, underbody guards etc. I tend to stick to under 70mph though. On long motorway and dual carriageway runs I get upwards of 21mpg

 

[Skydance]

Fuel economy is important for me otherwise I wouldn’t be able to enjoy the Grenadier on longer trips that initially bought it for. I often decide whether to take the MX5 or the Grenadier when there is just the two of us. But I do love the Grenadier because I don’t get intimated when someone’s drives so close behind me. Living in a big city with congested roads, I find some drivers are way too aggressive, in a hurry to get everywhere.

I do think in the UK everyone is conscious of fuel prices and I’m glad I bought the diesel.

 

[Tazzieman]

Fuel economy is important for me otherwise I wouldn’t be able to enjoy the Grenadier on longer trips that initially bought it for. I often decide whether to take the MX5 or the Grenadier when there is just the two of us. But I do love the Grenadier because I don’t get intimated when someone’s drives so close behind me. Living in a big city with congested roads, I find some drivers are way too aggressive, in a hurry to get everywhere.

I do think in the UK everyone is conscious of fuel prices and I’m glad I bought the diesel.

Diesel prices are going higher than petrol due to the mad mango, so it should even out.
Diesel puts food on the table so when there is a threat of hunger, people scrabble. Will be interesting to watch. Farmers in Aus are already unable ti buy diesel in some areas.