Join Date: Jul 2006
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Well, I would be inclined to treat most of the systems with a touch of contempt (until I verified that they were reading correctly). An accurate tyre pressure gauge may be all that's needed to restore your mpg. I believe that the gearbox will have some degree of software protection which will inhibit changing up/down to an inapropriate gear for the speed (1st at 50mph, 5th at 20mph) to give extreme examples, as my car will often overide my selection.
Short journeys are punishing on all cars man/auto, as the automatic choke is on for a greater percentage of the journey (at this time of year, perhaps all of it), plus, if you are up & down the gears a lot, then the torque convertor is using a lot of power (fuel). I would be inclined to check the pressures when cold (topping up where necessary), and check your mpg on a fast road where a steady speed (around 60-70mph)can be maintained. If it is still sub-40mpg, then a visit to the dealer may be worth considering.
Soomething worth bearing in mind is that all 'official mpg' figures were compiled in a lab using a rolling road along a 'virtual' test-track - they aren't accurate, but provide a benchmark for all cars currently sold.
All the best.
This job should never be complete - the day I think I've done it all, is the day I resign.
Currently in VelSatisfied's garage:
2005 FIAT Ducato 2.8JTD LWB Gran Volume, 2000 Kawasaki ZZR 1100 D7 'fullpower' in black + full GIVI & KAPPA luggage, 2007 MB R-Class 320 CDi Sport LWB uprated by Brabus to 300Bhp don't know if there's a 155mph limiter - will be fun finding out! 2004 Mercedes Vaneo 1.7 CDi Ambiente 7-seater