Thread: 2.2 Puma Defender Fuel Economy

Originally Posted by ninetubes

Looking for some advice on maximising my range in the scrub - think sand and gravel bush tracks 40-80km/h (excl the rocky, steeper, softer and more arduous sections)

I generally subscribe to the simple principals of; less revs and softly on the go-pedal, wherever possible

At lower speeds and especially in low range i try to just run at idle. When the tracks open up a bit and you get moving I try to aim for 1300-1500rpm. I feel below this might be laboring the engine a bit - is there any engine or drivetrain risk to running at close to idle speeds in 4th or 5th?

Any experience or recommendations welcome

Hi ninetubes
I like to keep the 2.2 chattering along at slightly higher revs than that. But it all depends on engine load. More load should be met with more revs, for oil pressure, cooling, natural inertia etc.
Personally, I limit load to something like 50% at 2000rpm for the 2.2 on a sliding scale (roughly speaking). Obviously its not always possible to do this though.
I'd avoid idle revs in anything higher than 3rd low / 1st high, again depending on load.

I get about 400 - 500Km max driving around about town in my 90.

I'm actually selling it if anyone is chasing a my15 90 in all black.

located in victoria.

Cheers

Is the peak power output at about 2000rpm? If so, it should not be labouring or over-revving around that.

Originally Posted by DiscoMick

Is the peak power output at about 2000rpm? If so, it should not be labouring or over-revving around that.

Exaxtly what I believe.

Torque is acceleration so the defender speed up at around max torque at 2k rev

However the max power is at 3.5k rev
So if you want to maintain that high speed on highway you probably should sit at 3.5k rev at 6th gear.

I also believe the bas remap moVes these number forward
This is my understanding....

On the other hand, I know what ninetubes means.

It is less likely to break traction with the defender idling so that's why sometimes you can get up a slope with an idling 1st low But you can't if you give it some gas....

Stupid manual gearbox

what i mean is; reducing rpm is reducing swept volume and hence fuel consumed. eg travelling in 5th at 1200rpm instead of 4th at 2000rpm (not exact numbers, example only).

and the question being: How low can you practically go ?


To put this into context, at easter we did about 900km offroad averaging 50-60km/h & I was very close to the extent of my 115L range (without jerries). So keen to hear what anyone has to say about how i can maximise it SAFELY, as we have longer trips planned soon.

Originally Posted by Beery

Hi ninetubes
I like to keep the 2.2 chattering along at slightly higher revs than that. But it all depends on engine load. More load should be met with more revs, for oil pressure, cooling, natural inertia etc.
Personally, I limit load to something like 50% at 2000rpm for the 2.2 on a sliding scale (roughly speaking). Obviously its not always possible to do this though.
I'd avoid idle revs in anything higher than 3rd low / 1st high, again depending on load.

thanks beery, good point re oil pressure and coolant circulation etc. Don't want to find out i've sacrificed engine wear to save on carrying 1 can of extra fuel

Then bad idea to lug the engine on highway

Get a diagnostic tool and monitor engine load and temperature. (Oil temp I believe in 2.2?) And also egt.

My 2.2 puma really don't like high way driving. Egt will approach 500c if rev is too low