Good MPG is possible with a petrol 4.0 litre

I just read through the happy reports of fellow members with Disco's hovering around the 29.1 and near 30.0 MPG mark - but I am betting these Landies are all diesel - correct?

The good news is that you can increase the mpg in a petrol engine (I own the 4.0 litre Gems in a 1997 Disco I) - but it takes some labour and money (forget about the cheapo fixes - such as the Juice Box - they do nothing at all)! Here's what has finally worked for me:

1.) I opened up the exhaust with a good set of headers - this improved the mpg only marginally though.
2.) I installed the Safari snorkel and this really improved the mpg - to the point that the expense on the exhaust work now looks worthwhile. The lesson here is - you have to get your Disco petrol engine breathing easier from both intake and exhaust - as just fixing one will not do the trick entirely all by itself - but both done together - will make a noticeable improvement - all down the line!

I am now getting around 20 mpg (don't laugh - as that beats the hell out of the 11.5 to 12.0 I was getting before).

I fully expect to further increase my mpg by putting on some seriously reduced-restrictive (Magna-flow) mufflers (yes, I now, the Landy will sound somewhat more aggressive after this op) and by replacing my now defunct O2 sensors which have about 147,000 kliks on them and are throwing codes at me.

I'll keep you informed as to the final mpg rating.

20 mpg ...you're kiddin ...right!??

as i said in the other mpg thread i'm lucky to get 14.4mpg ...and that's with a snorkle and a modified exhaust.
okay so maybe i thrash her a bit on the straights and live in a hilly area, but sheesh, even if it was on a long levelish run at a steady 60 no way would i get 20mpg.

Hi Becs,

What have you done to the exhaust?

My 20mpg may be inaccurate as I was guaging from when the fuel light came on and I have since discovered that it can come on late or early - depending on what angle the vehicle gets parked at over night.

You have to remember also that 14.4 mpg for a V8 gasoline/petrol engine is quite respectable; Ford is just boasting about their most advanced V8 in a a half ton getting up to 15 mpg with a hi-tech ability to shut down 4 cylinders and make it run like a four cylinder until you need the V8 power.

I've just sold my BMW 740i V8 and bought a Discovery .........

The BM did an average of 28mpg motorway driving and 20 - 22mpg around town - I guess that's down to gearing and tuning?

Wolf...you and I discussed this before, but I am curious about the snorkel. In high speed running the funnel at the top might assist with a little forced air induction but cant see it making that much difference. I would have thought the headers and exhaust would have made the most impact. Perhaps its thge cool Canadian air.

Only way to get good fuel consumption from a V8 is to leave it in the shed.

well said, that man.

you could put it on a trailer and tow it everywhere with a diesel

Nice to know------ but will stick with Diesel mysel-----300tdi manual with overdrive 30+ to the gallon b-b

OutbackJack said:

Wolf...you and I discussed this before, but I am curious about the snorkel. In high speed running the funnel at the top might assist with a little forced air induction but cant see it making that much difference. I would have thought the headers and exhaust would have made the most impact. Perhaps its thge cool Canadian air.

Click to expand...

Hi Outback,

I know - but the thing is I think the extra air is simply enhancing the major exhaust work; besides - Oz knows how to make great snorkels (mine is the ARB)!

Whatever it is, it is really helping - I just think its the combo of the two.

Get a mutipoint LPG fitted. Then the fuel is half price, so effective consumption is the same as a diesel, but you get to overtake people!

i resemble that remark.
i overtake lorries. well sometimes anyways.