ONLY 20 MPG DISCOVERY 300

[JUST PANTS]

I am only getting 20 - 22 mpg from my 300tdi auto.
Best i have had in the last few months is 24 mpg over a 450 mile round trip.
EGR valve removed,air filter clean no black smoke drives all ok.
Does any one have any idea's its starting to hurt now.

[edmason]

Presume you've checked for binding brakes? Low tyre pressure? Oil in turbo, or collapsed turbo hose? Damage to exhaust if offroaded?

[cpas]

I only ever got 24mpg on average from my 1997 300TDi manual, so 20's not that bad for an auto!! If it's a later car like mine, it may have a cat (even on a diesel) as well as the EGR system. Such cats were an early development in Diesels (so not yet developed) and did nothing for MPG.

[300bhp/ton]

All 300Tdi Disco's have cats.

With a manual I'd expect mid to high 20's as a rule. So a tad lower with diesel, but 20mpg does seem a little on the low side of things.

How are you working out mpg?

What diesel are you using?

What size and type of tyres are you running?

Do you have a roof rack?

What types of roads do you drive on?


You say it doesn't smoke, well that might be part of the problem. Auto TDi's are, shall we say a tad sluggish so need to be gunned just to keep up with traffic. Tweaking the injector pump and maybe adding a bigger intercooler would free up a lot of HP/torque. This means you should be able to drive more gentle and see better MPG.

My 200TDI manual see's aruond the 24mpg mark as a rule, but I'm running on 33" fairly extreme off road tyres.