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Fuel consumption

Posted: Tue Aug 21, 2018 8:53 pm
by Roymck
Is there a lot of difference in fuel consumption between a 2000 and a 2.5 pi. What would you expect mpg on a 2.5 pi.

Re: Fuel consumption

Posted: Wed Aug 22, 2018 11:04 am
by johnnydog
A correctly set up PI can be more economical than one running on carburettors. However, unless you are proficient in setting up a PI, invariably they can be more thirsty. It possibly also doesn't help as the nature of the beast (a PI) probably encourages you drive more spiritedly!
I used to get top 20's from a PI many years ago when on a run, but when they are out of tune, it can be as low as early teens!
It makes sense with a PI to esnsure that it is properly set up - even if you are paying for someone else to do it as long as they know what they are doing, it will be cost efficient in the long run.

Re: Fuel consumption

Posted: Fri Aug 24, 2018 11:48 am
by M5driver
Hi having owned several 2.5pi's saloons and estates it does depend on your right foot. But on a long run cross country 26/27 mpg, motorway you can get 30 keeping to the speed limits. Around town in a cold winter on a short journey (unlikely these days) 17/18 mpg. Towing expect very low 20's even less if hilly.
A 2000 will have to work harder if used to the limit hence using more fuel. My first 2000 never did more than 20/22 mpg. There was no overdrive on the car. That's another thing to consider a man/od car will use less fuel than auto.
Hope this helps. Importantly the pi must be correctly set up and the engine in good order with a idle vacuum of 14 to 16 Hg or thereabouts.

Re: Fuel consumption

Posted: Fri Aug 24, 2018 11:48 am
by M5driver
Hi having owned several 2.5pi's saloons and estates it does depend on your right foot. But on a long run cross country 26/27 mpg, motorway you can get 30 keeping to the speed limits. Around town in a cold winter on a short journey (unlikely these days) 17/18 mpg. Towing expect very low 20's even less if hilly.
A 2000 will have to work harder if used to the limit hence using more fuel. My first 2000 never did more than 20/22 mpg. There was no overdrive on the car. That's another thing to consider a man/od car will use less fuel than auto.
Hope this helps. Importantly the pi must be correctly set up and the engine in good order with a idle vacuum of 14 to 16 Hg or thereabouts.

Re: Fuel consumption

Posted: Fri Aug 24, 2018 11:49 am
by M5driver
Hi having owned several 2.5pi's saloons and estates it does depend on your right foot. But on a long run cross country 26/27 mpg, motorway you can get 30 keeping to the speed limits. Around town in a cold winter on a short journey (unlikely these days) 17/18 mpg. Towing expect very low 20's even less if hilly.
A 2000 will have to work harder if used to the limit hence using more fuel. My first 2000 never did more than 20/22 mpg. There was no overdrive on the car. That's another thing to consider a man/od car will use less fuel than auto.
Hope this helps. Importantly the pi must be correctly set up and the engine in good order with a idle vacuum of 14 to 16 Hg or thereabouts.

Re: Fuel consumption

Posted: Fri Aug 24, 2018 4:42 pm
by johnnydog
Have you got a twitchy finger Chris? :lol:

Re: Fuel consumption

Posted: Sat Mar 02, 2019 3:18 pm
by Peter Douglas W
I had no problems in gettingh 30 + Important is not the PI bits it is everthing else. Good battery. Throttle valves working correctly. The ignition a 100%. Good earthing. Good compression. All these things indirectly change the vacuum values. This means that the Metering unit and pump will not work as designed.

Re: Fuel consumption

Posted: Sun Mar 10, 2019 6:49 pm
by Andy Thompson
I had a LHD 2000 - bog standard that I drove carefully so max ~ 70mph - cruising long distances at about 60mph as I was in no position to rebuild the engine and it gave 32-35mpg consistently (didn't really change after fitting overdrive, I just drove a bit faster.