[rogan]

I've done some searching and have come up a bit blank.

4.6 P38 on 96ron unleaded. I'm averaging ~23litres/100km in city traffic. It's semi rush hour driving, not really stop start but more 30kmh crawl, and round town at 50kmh with a short burst on the m'way at about 90kmh. I don't think I'm heavy footed but I'm staggered at how much petrol I'm going through. Using this calculator this equates to about 12mpg. Engine runs smoothly and doesn't seem to have any flat spots.

I have a 5series BMW with a 4.4 V8 and I'm probably using twice the petrol in the P38 doing the same type of driving (but I'm more heavy footed in the BM).

Is this normal or do I need to start checking oxygen sensors etc.

 

[kmagnuss]

Possibly a tiny bit low. I avg just over 16 mpg, but it's mostly all highway and 50 mph zones with few stoplights. IIRC, the window sticker says 12 city - 15 highway.

 

[BargePilot]

My 4.6 does about 20,30 l / 100km in city traffic and 11, 12 l / 100km on the highway, where I mostly drive 90 km/h.

Overhere we can choose between '95' and '98' at the pump and I don't know how that relates to 96ron.

btw: I'd love to have a V8 beemer as a runabout. 8)

 

[mekadodo]

I get about 22L/100k on 98RON. Lowest its been was around 14L on a long highway trip

 

[81stubee]

I get around 19L/100km in the city, and 12-13L/100 on the highway. I have a 97 4.6 with 9.55:1 compression and only run 98RON fuel.

You may find it has something to do with the fact that your car may not have been fitted with oxygen sensors, which enable the ECU to more accurately meter fueling and adapt to the environment. I don't think early P38's had them fitted.

Stu

 

[Selby P38]

G'day mate ,same as Stubee mines on LPG single point 19lt/100klm 12/13lts on the open,mines done 200,000klm 1996 HSE 4.6 low comp no oxygene sensors.

 

[Shadow Keeper]

Mine runs at just over 16lt/100km in the city and as low as 12lt/100km country. The White Peril is a 96 4.6lt HSE..

 

[john-sussex]

well if you remember that the US/UK gallons are different I get with general running around mixed driving 19/20 MPG UK for a 4.6 Thor engine. Driven on a run or VERY carefully I can out do a friends V8 Diesel Sport!

 

[996TURBO]

22 liters paris city driving
11 liters at 90 kmh on non highway roads
15 liters at 140 kmh

On fuel measures

 

[rogan]

Thanks, so economy is not unusually bad. ****.

Have read some of the cat removal threads and that could be a option. I couldn't give a rat's arse about added performance, but is there much of an eceonomy gain from getting rid of the cats.

 

[996TURBO]

Mine is decatted. I like it. MOT do not want it but MOT guy is a friend of mine

 

[rogan]

Don't think we have de-cat issues with WOF (NZ speak for MOT) here. Would check before removing.

As a side, my BMW 540 (M62 engine) is doing 14.1 l/100km at average 37kmh. Kerb weight is about 1750kg, but add another 100kg for stuff I've added.
RR P38 is 2220kg according to my quick google.

 

[John W]

Mine was decatted when I had it in South Africa.After bringing it to the UK,I had to have Cats fitted in order to obtain an MOT.I see no difference in performance or fuel consumption.I do not derive it on the limit and am quite light footed and return 16.5/17 mpimperialg mixed driving and 19.5 on motorways at 70mph.Would be nice if the mpg could be improved! :lol:

 

[rogan]

Just had it serviced. When I picked it up and asked if they'd found any problem with the fueling they laughed at me; was running very very rich. On way home in stop/start traffic I averaged 18.5L/100km, so there's a 5.2L/100 km improvement !!

 

[Selby P38]

Just had it serviced. When I picked it up and asked if they'd found any problem with the fueling they laughed at me; was running very very rich. On way home in stop/start traffic I averaged 18.5L/100km, so there's a 5.2L/100 km improvement !!

there ya go your on the mony now :thumb:

 

[mekadodo]

Haha. Got mine back from the shop for lifter problems, and when i flicked over to the fuel usage meter, it read 42L/100km :shock: :shock: :shock:

Double checked the mileage to make sure they hadn't gone joyriding. Probably caused by having the car sit still and the engine running/revving

 

[Selby P38]

Haha. Got mine back from the shop for lifter problems, and when i flicked over to the fuel usage meter, it read 42L/100km :shock: :shock: :shock:

Double checked the mileage to make sure they hadn't gone joyriding. Probably caused by having the car sit still and the engine running/revving

Thats right you don't move the fuel goes up she has to move to do the ratio ,reset and she how it goes :thumb: