Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: 4huftys on 06 May 2009, 17:26:26

Title: Fuel economy v6 2.6
Post by: 4huftys on 06 May 2009, 17:26:26

Could any one explain why on one of our omegas we can only achieve 18 or 20mpg. The only difference is this one is on lpg all the others achieve 28 to 30mpg are all around the same age serviced well VX parts oil etc.
Any ideas please.
Dave

The 18 to 20mpg is on petrol as well as lpg

Title: Re: Fuel economy v6 2.6
Post by: ians on 06 May 2009, 17:28:57

I thought LPG did come in at lower MPG :-/

The thing that made a significant difference on my 3.2 was changing exhaust (the old one was shagged and I suspect particlaly blocked.

Title: Re: Fuel economy v6 2.6
Post by: Darth Loo-knee on 06 May 2009, 17:29:12

I believe you don't get as many miles per gallon on gas, aren't 100% sure though :-?  as I trying to stay away from gas  :D

Title: Re: Fuel economy v6 2.6
Post by: 4huftys on 06 May 2009, 17:39:22

I know you get slightly less mpg on lpg but this is the same running on petrol.

Title: Re: Fuel economy v6 2.6
Post by: ians on 06 May 2009, 17:48:28

a good service to start with I suggest.

Title: Re: Fuel economy v6 2.6
Post by: 4huftys on 06 May 2009, 19:00:46

vehicle is fully serviced

Title: Re: Fuel economy v6 2.6
Post by: zirk on 06 May 2009, 19:30:52

Sounds about right on Gas, normally 80 to 90% less, Petrol seems a bit down though.

Title: Re: Fuel economy v6 2.6
Post by: vc009 on 06 May 2009, 19:58:46

i drive a similar v6 on lpg/petrol and i average around the same. Firstly because lpg burns faster so mpg drops quite a bit even though u still save money. having driven a few  few lpg cars in the past ive noticed that after conversion and running daily on lpg they start averaging similar on petrol as well. Have you changed your petrol fuel filter? people tend to avoid this and forget about it specially when the car is a lpg one.

Title: Re: Fuel economy v6 2.6
Post by: Martin_1962 on 06 May 2009, 20:43:35

Thermostat?

Title: Re: Fuel economy v6 2.6
Post by: Entwood on 06 May 2009, 21:49:50

Quick reason for LPG consumption being higher than petrol ....

All engines burn a MASS (weight) of fuel and air, not a volume.. (thats why we have a MAF - Mass Air Flow sensor and performance is better on cold wet days ...) yet the fuel is sold by volume. LPG has a lower Specific Gravity than petrol .. so a litre weighs less (or a gram takes up more space - your choice).

If fuel was sold by weight, the consumption in miles/kilogram would be identical, as thats what the ECU does .. :)

Now this implies that your LPG consumption is about right .. but your petrol consumption is high.

HTH

Title: Re: Fuel economy v6 2.6
Post by: feeutfo on 07 May 2009, 00:15:46

multi rams working? Clue to this would be any steps in the power delivery or sluggishness low down. Any hissing from vac system for a second or 2 after engine stops? Any running issues?