4.6 mpg?

martynv8 said:

No, if im doing a constant 70 on a clear run on motorway (usually sheffield - london) i average 20-21. If i'm booting it then around 17-18.

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When I had my first P38 (4.6 HSE) I would be driving round the M25 from around J12 Chertsey, all the way round to J2 A2 then into Stratford....then as the work moved further out it was A2 to Ebbsfleet, then M20 to Ashford (Kent).....

I would average 19-21 on those trips.....

Luckily mine is not a daily commute - maybe once a week( i work from home but our offices & warehouse are in Perivale). I can get there & back on a full tank of LPG...if i'm careful.

My 4.6 used to get an averge of 11mpg over 1000miles mostly stop start driving around leeds

Ok, done around the 152 mile mark driving Boston to Beckenham in kent. Mostly 60 and 70 mph roads/motorway. Had around 2 miles of roadworks where I was at a stand still. Only achieved 20.2 mpg so not as good as sometimes but not bad for the RR!!

How does that compare with the 4.0?
I had a 3.9 in my old Disco (sameish engine right...?) and that barely got above 5mpg

4.0 and the 3.9 are the same engine...same displacement, it was rebranded the 4.0 for the P38 to distinguish itself apart from the classic.....a few different ancillaries were fitted for the P38 but the engine itself is the same!!!

Our P38 4.6, mostly used for short journeys round town, has a long-term average of 13.4mpg and 17mph.

OK, first of all I said I covered 152 miles, it was 142 miles, just got back with a total of 284 miles. On the way back I drove with 'enthusiasm' and the whole 284 miles showed an average of 18.4 mpg. Read between the lines......................the RR can reach a ton+ no problems and even kicks down at 80mph+ in sports mode...allegedly your honour!!! The mpg was taken from the on board computer, when I fill up tomorrow I will work out the fuel used and true mpg to see if there is a difference.

Filled up today, cost £96.00.
96 divided by £1.367 per litre = 70.23 litres used,
70.23litres divided by 4.54 = 15.47 gallons
284 miles divided by 15.47 = 18.36 miles to the gallon

So the on board computer is very accurate...on mine at least!

My 4.0 does about 19 mpg on the motorway and round town, erm, a lot less!

Around towm mine shows about 9.4 mpg!! The fuel going to the chip shop costs more than the cod and chips itself!