[ROVERNET - UK] thristy P5????

[Ron Venter]

Ben,
          So much depends on the type of driving. For a heavy car such as 
the P5, a lot of stop start driving will play havoc with fuel consumption, 
but on the highway at a steady 65 to 70 mph in overdrive it should better 
30mpg Imp, or 25mpg US.
         For a car that is little used, perhaps the first thing to check 
for is binding brakes. Pistons can rust and partially seize, and also brake 
fluid seeping (just slightly) past the seals can get quite gummy.
         Next check the colour of the plugs after a run (with as little 
idling as possible). This should give you a clue as to the mixture.
         Is the centrifugal advance on the distributor free? This may be 
something else to seize up over the winter. Do you set the timing by the 
book or by trial and error to "just before pinking"? (I don't know which is 
best!)
         Finally, I have heard but do not have any direct experience, that 
some mufflers can collapse internally producing excessive back pressure. I 
don't know if that is possible with P5 mufflers.
         Please let us know if you find anything.
         All the best,
                      Ron Venter (on Vancouver Island, but willing to 
travel to Prince Edward Island to relieve you of your P5).

At 07:58 AM 05-07-04, you wrote:
>Hi Folks
>              I don't use my 1967 P5 Mk3 alot, just a bit of summer driving,
>maybe 300-400 miles per year. It seems to be very heavy on fuel , 12- 14
>mpg. I'm wondering if this is common on the P5? I would have expected better
>perhaps closer to 20mpg, my car is a 4 speed with a working overdrive. The
>carb has been rebuilt, top end redone with all new exhaust valves, petronix
>ignition system fitted. Everything is as it should be to the best of my
>knowledge? any ideas???
>                 Regards  Ben