Hi guys

Please can anyone with a 90 2.5TD converted to either a Defender 200TDI or a Discovery 200TDI tell me what MPG's you all get from your engines and please can you state wether you have a defender engine or a discovery engine as with mine a 2.5TD converted to a Defender 200TDI i am only getting 20mpg

ok the pump was tweaked before i bought the 90 with the defender engine already fitted so not sure what's been done there and i have 265 special track tyres fitted and a straight through exhaust aswell but everything else is std but i have been told even with all this fitted i should be getting better mpg than what i am getting now.

so i am just trying to find out if i am expecting too much out of a defender engine and need to go for a discovery engine instead, what do you think

Iv got a factory fitted 200tdi and last time i worked it out i was getting 18mpg, iv got 265 mud tyres on, winch, spots and all that.

I also drive like i stole it though

Def 200tdi in an SIII 88 with '90 diffs and overdrive used to top 35mpg once away from home and short journeys. Trailmaster (road bias) tyres helped. If you don't 'need' the pump tweak you'll save yourself a lot right there!

MPG is almost always about driving style, followed by what accessories you have. If you utilise that pump tweak by having a leaden right foot, you will use more fuel. If you have tyres with a high rolling resistance (e.g. Very knobbly), or a roof rack with masses of lights in it, then you will use more fuel to maintain the same speed.

I've averaged 18mpg in my V8 Disco 2, but I do mostly long (200mile+) runs and I don't accelerate hard. The last run I did I held the speed back to 60mph (instead of my usual 75) on the motorway, and I got over 22mpg! But I have no roof rack (not even bars) and snow+ice tyres, not mud. The only excess weight I have is a winch.

Right i have just been trawling the net and found out that there are 2 version of the transfer boxes on a 90 / defender 90 200tdi which is a 1:1.6, and a 1:1.4 so with mine being a 1988 model 2.5td converted to defender 200tdi i am assuming it still has the original gearbox fitted with the original 1:1.6 transfer aswell.

I know it won't make a huge difference but fitting a later 1:1.4 transfer box may help sort the mpg out better i know i could go for the disco 200tdi transfer box which is 1:1.2 which would be better but think it would be too over geared and on hills as i would be up and down the box all the time so think i will keep a look out for a 1:1.4 instead

It's your tyres. My 200tdi 110 does 30mpg driven carefully and never less than 25mpg caning it on the motorway or towing. But I have proper LR wheels with 7.50's on.

My 90 with Discovery 200 tdi conversion with Disco box and a 1.2 Disco transfer box did 28 to 30mpg driven carefully with 75% town driving.
I got 26 towing a car on a 1 ton car trailer (heavy)

I found the 1.2 transfer box a little high geared with my tyres which are standard land rover 110 sizes and about 31 inches tall.
It would only just run at 30mph in fourth about 1200/1300rpm which was no good, if traffic slowed to say 27ish mph then I was down to third.
Because it was so high geared and I only travel about 55 on the motorway the fuel consumption could have been better, around 32 on a run. Any hills and it was down to fourth unless travelling at sixty plus then it was fine but still using fuel because of the roof rack and higher speed.

I have just replaced the gearboxes with an R380 and a 1.4 transfer box which will have the engine spinning at a better speed for economy around town and at 50 mph on the A roads.

Like a mountain bike really, no point in having a very high gear its better and easier to pedal faster using less energy than standing up on the pedals to keep speed up. My theory anyway and it was true of the old underpowered trucks years ago, gear them up with higher diff and they used more fuel.

My factory 200tdi 110 with 78k on the clock returns 25ish mpg.

I have spots, knobbly 265 tyres, winch, etc.

Also if you've got a roof rack on take it off cos it's costing you a fortune. An old 19j 110 we had a few years ago went 10mph faster once I took the massive rack off it. I never really measured the fuel consumption but it must have made a big difference.

200tdi and transfer box from a disco fitted to a 110 with 750AT tyres, 30mpg locally but dropped to 25 when in was in a hurry up the A1