Drinking habbits

[Deleted]

Now that I have cured nearly all little flaws on my coupé I am looking forward to sunny spring days and plan to use it mor often in everyday traffic. It is so much soothing and even makes the others around you less aggressive.

One thing puts me off. Fuel consumption.

Just to know if mine is more or less average: I drive in town or on the autobahn, not so much on ordinary roads. On the autobahn I sometimes do 90mph, most of the time I cruise along at 80mph.

Under these conditions the car averages between 15 and 20 mpg.

Any similar or differing experiences?

[Deleted]

Sounds much like my P5b coupe figures.
If I keep to 65-70 mph and gentle acceleration, I have achieved about 22mpg.
My car is standard twin SU V8 with electronic ignition and no engine driven cooling fan (Electric fan thermostatically controlled is fitted) and has manual choke.

Cheers

[dorsetflyer]

All the figures quoted seem to add up. Remember an awful lot rests on the way they are driven. A heavy right foot can keep the consumption figures between 17 and 20 mpg. But a light foot and anticipating changing conditions ahead, can make a big difference to the figures.
It seems the modern day trend is to accelerate until the last possible moment and then brake hard, hence all the start stop conditions on the motorways.
When these cars were new very few ever drove in that manner.
In my 3 litre on a long run I get 22 to 23 mpg, and in the 3.5 litre I can get 25 to 26 mpg. So anything between 20 to 26 mpg is good.
Obviously driving at 80 to 90mph the consumption is going to suffer substantially. But then those who had these cars from new didn't worry that much about fuel consumption.

[dorsetflyer]

There are also many other things that can affect consumption figures like tyre pressures, if too soft they increase consumption.
Similarly all brakes must be free running with no binding at all.
In other words the greater the rolling resistance the worse your figures will be.

[Phil Nottingham]

My Auto 1964 Coupe does 16mpg locally and 24 long trips.
My P5B saloon does 18mpg locally with 23-24 on long trips with high speed motorway driving.

Locally involves commuting to work every day with a round trip of 24 miles - it does not seem to make much difference whether its winter or summer but our 1958 S11 Land-Rover petrol seem to do less than 14 mpg anywhere!

[Geoff Arthur]

My P5B coupe has a load of mods including Holly 390CFM carb, Vitesse pistons, Offenhouser heads etc etc. This enables it to return a happy 22mpg if driven sensibly. Unfortunately it goes so well that I find sensible is not the thing I do best, so last time I did a 100% accurate check it came out at 17.63mpg. Bear in mind that consumption is usually worse than that recorded as radial tyres exaggerate the odometer reading. Gaydon is an exact 100 mile trip from where I lived in Hampshire but the P5 came up with 108. Easy answer is to fill it up and drive it til empty and dont think about it, just enjoy your smile.

[stantondavies]

Hear, Hear!! I get about 18mpg from my 3 litre and I don't spare the horses! (22mpg is achievable on long journeys.)