Superb fuel economy

[christopherspeed59]

Drove from home to Edinburgh yesterday, 420 miles at an average speed of 69mph and fuel economy of 41.9mpg. Well pleased

[J44EAG]

Birmingham to Portsmouth in 4 litre V8. 25mpg pushing on a bit on occasions. Have achieved 31mpg but at 56mph with very light foot. Not bad for a tweeked car set up more for fast road work than economy.

Mike

[redcat]

Early days yet for me but on a 150-mile round trip to York, sticking to the speed limits and using the cruise where possible, computer read 51mpg when I got home.

Redcat

[richardtoulouse]

I use my S type V8 4.0 to drive from south of france to normandy (Toulouse to Cherbourg).
I spend 17 mpg !
Motorway at 87mph, it is the best efficency. As soon I drive on local street, the efficiency decrease !
It should be noted that my car is not old at all, less than 50 000kms !

[J44EAG]

Most cars are designed to be at their most economical at 56mph. I have achieved 31mpg with my 4 ltr V8 if I have carefully driven at that speed using the cruise control. That does improve mpg.

At 70 mpg, I can achieve 28mpg.

On most long distance runs, I would expect to see 23mpg which includes motorway and duel carriage way use. If there are roundabouts to be negotiated on the journey, 21mpg is normal. If I use the power available from the V8, then I would expect to see the figure drop to 19mpg.

In a city or town driving situation, 17 or 19 mpg is the usual return as the care does not often use a gear higher than third. Only when the car reaches 50mph is it able to use the "overdrive" fifth gear.

Remember that this early model V8 only has five gears and is not as economical as the more powerful 4.2 V8 which is good for 10% more fuel economy due to modifications to the engine management systems and the six speed gearbox.

The early 4 litre V8 cars use more fuel than any of other cars in the range, other than the S-type R which car be very thirsty if driven around town or fast in an out of town situation.

Having owned both V6 3 litre and V8 4 litre S-types, I note that the 4 litre uses 25% more fuel in general usage than the smaller engined V6. However it is a much easier drive and both the engine and the gearbox do not have to work so hard.

A small extra economy has been noted when I have used Premium grade fuels. However the additional cost of using that fuel hardly makes the effort of using Premium fuel worth while. The benefit if there is one, is a slightly sweeter running engine. The effect however again is not really worth the extra cost.

The design of the 4 litre V8 is now around 15 years old and technology has moved on. With increased technology comes cleaner engines and increased fuel economy. Realistically, our old V8 engines can hardly now be described as clean or indeed very efficient when compared to newer designs. I certainly regard my V8 as being something of a dinosaur.

Mike

[richardtoulouse]

I said 17mpg?
I could made en error to translate from l per kilometers.....
My average fuel cunsomption is 12l/100 Kms!

All my others car use less fuel... No, it is wrong, my XJS !!!!!

[redcat]

Early days yet for me but on a 150-mile round trip to York, sticking to the speed limits and using the cruise where possible, computer read 51mpg when I got home.

Redcat

You obviously guessed it but I should have said this is a six-speed deisel (manual box).

Redcat

[J44EAG]

Great street cred for robbing a bank. In such an instance who cares about the fuel consumption!

Here is Tiff, Quentin and an unusually tidy James May reviewing the early model with Mr May demanding an S-type to do the job.

http://www.youtube.com/watch?v=IkWHG-Vq ... re=related

Mike

[msdsx]

Recent round trip to Central Birmingham from Portsmouth via Croydon, 418 miles, average speed 58mph, 29mpg. OK, lots of motorway miles but a fair amount of town driving too. Not bad for an STR!

[redcat]

Over the last 2,000 miles of mixed motoring the computer is showing 43mpg.

Redcat

[MCALLISTERABERDOUR]

Hi,
I have a 2004 2.5 V6 with the six speed auto box. I have bought a Bailey caravan of 1150kgs tow weight which is a perfect match for the car according to the tow car stats. Has anyone any info on towing with an S type of 2.5 or 3 litre engine size and what kind of mileage can I expect. At the moment I average around 26/27 and anticipate dropping to around 20/21 to the gallon when towing. Any takers?

[oldtimer]

Hi All,
It is not difficult to get down to 9mpg in my old V12 XJ on Stromburg carbs!
I have only checked the fuel consumption of my 3Ltr V6 Manual S type once. That was all motorway except for a couple of miles or ordinary roads at each end. With the trip set to instant fuel burn and driving very carefully at between 68mph and 72mph I achieved 36.??mpg. I did like the 99.99 bit down hill but how jolly boring. Never again.
How I envey the ''French guy with a little bit of English'' enjoying the roads over there, traffic , what traffic. We go to France most years with our caravan ( All up weight 23cwt)and use the
S Type to tow. I think the roads must be part of the attraction, well yes, the wine is OK!
I find that 70mph is a comfortable speed for me and with such light traffic the miles quickly clock up.I would also say it is the most stable of tow cars I have had. We give MK a wave as we pass on the Ferry, he probably does't see us , he keeps dropping his specs into his drink.
Oldtimer

[J44EAG]

I don`t drop my specs in my drink, I drop them in the drink....That makes a big difference. They kind of fall off the enda me nose into the water. Then I have to fish them out with a boat hook or a kiddies shrimping net or get in the mud myself! Three times this year. Specs arn`t the only thing I`ve dropped in.

During a recent storm I lost a standard S-type back exhaust box off the rack on the cabin roof. Last seen floating up the Creek towards the M27 before it sunk! Not seen it again even though have walked the low water mark at bottom low spring tides.

My old trombone still lurks at the bottom of the harbour after someone objected to my appalling rendition of Ashton, Gardener and Dykes "Resurrection Shuffle". Never did get the same note twice from that accursed thing. Twelve feet of wound up brass misery. Probably just as well I never recovered it.

Next time you pass through Pompey, Phil, you better come and see how we do it down here. Bring yer wellies.

Mike

[oldtimer]

Hi Mike ,
We night stop at Rooksbury Park camp site prior to departure on the Ferry so I might well take you up on the offer
Oldtimer