Using More Fuel

Our work Defender, 2014, was managing about 500+ miles per tank, but last week (first time driving it for a while) I drove 44 miles to fetch a works cabin and tow it back 44 miles. It weighed in at 2.1 tonnes. Now the tank was full and when I got back it was almost at half!?!?!?!?!

I filled it and drove a total of 180 miles round trip and used the same amount, give or take a litre.

The other day, I drove it 269 miles and used 48 quid of diesel. The journey was constant 105 miles with an empty bowser, 59 miles with it full and returned 105 miles with it empty.

Today, it was off & on with bags of power and using little fuel, then little power and using more fuel.

I also made an arse of a gear change today... I was in 4th, hammering it and going into 5th when I hit a massive pot hole as I was going through the gate into 5th and managed to go into 3rd instead, so the RPM was mental at around 5500 for all of a second until I hammered the clutch back down & corrected my booby, but not before the engine management lamp lit up and limp home kicked in. I selected neutral and switched off, restarted and off she went, but still with the management lamp lit.

No lasting damage, but the power has been constant since with no loss...

Idea's?

I'm thinking she needs a new fuel filter and the brakes looked at.

Anyone?

DPF blocked?

Over revving can damage the engine, what is the red line on that unit?

lightning said:

DPF blocked?

Over revving can damage the engine, what is the red line on that unit?

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It is possible the DPF is slightly blocked, but as I am not the regular driver, I can't say for sure. Normally, she pulls like a train, but a couple of times she was lacking.

Today, I filled the bowser 3 times so when it's laden it weighs almost 3.5 tonnes and she pulled it no bother at all.

I have no idea what the red line is, but she stops at 4500rpm normally. Like I say, it feels fine, no noises, no smells, no other obvious damage.

But the point being that I did about 280 odd miles today and used 3/4 tank.

It was that short trip of 88 miles and using half a tank that threw me!

if it's not a constant it's going to be hard to find.
I doubt it's fuel filters as once they Block, they Block.
I'd guess something like a egr valve sticking open or a mass air flow meter or something else on its way out.
I'm not familiar with the puma so I'm of no real help. Does it smoke or do anything obvious when is runs flat?

Did you fill it before towing the load or were you just relying on the gauge saying full?
Fuel gauges sadly are not linear, basically they lie!

If you were towing 2.1 tonnes and hammering the engine (sounds like you do drive it hard) it might only do 15mpg. My friend had a Puma 90 and it only did 25mpg in normal driving.
so in 45 miles you might have used close to 15 litres of diesel.
If the tank was not quite full that might be enough to drop the gauge towards half from indicated full.

Doo said:

Our work Defender, 2014, was managing about 500+ miles per tank

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Are you sure?

Don't Puma's still have around 12 gallons of useable fuel load? 500 miles / 12 gallons is 42mpg. Which I find somewhat unlikely in a Defender. Land Rover rate the Puma at 30.1mpg max and only 27.7mpg combined. And that's for a 90, less if it's a 110.

Doo said:

The other day, I drove it 269 miles and used 48 quid of diesel.

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Assuming £1.10/litre, that is 28mpg..... which is bang on what Land Rover claim they will do. Are you sure you aren't getting confused with how big or small the fuel tank is?

Hi all, ok, the 28mpg sounds correct, so why would it (for no apparent reason) use almost half a tank doing under 90 miles, half of that with the cabin?

I wasn't hammering it because 2/3 of the journey to Aviemore was through Average Speed Camera's, so 60mph down and 50mph back.

No smoke of any persuasion... I wonder could it have been a sticky brake?? Although no unusual smells or smoke off them to signify a problem.

Yes it was full and the gauge on the Defender is pretty reliable.

Strange one

Doo said:

Hi all, ok, the 28mpg sounds correct, so why would it (for no apparent reason) use almost half a tank doing under 90 miles, half of that with the cabin?

I wasn't hammering it because 2/3 of the journey to Aviemore was through Average Speed Camera's, so 60mph down and 50mph back.

No smoke of any persuasion... I wonder could it have been a sticky brake?? Although no unusual smells or smoke off them to signify a problem.

Yes it was full and the gauge on the Defender is pretty reliable.

Strange one

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Probably measuring error. You never get accurate figures from a gauge.

Brim full, use 2/3rds of a tank. Brim again, calculate the mileage against the litres on the fuel receipt. That will give an accurate figure.

I DID fill it after the usage and it was about 40 quids worth. I normally do big miles so if I have used more than quarter, I neck it. Nothing to do with the gauge...