350 miles per gallon? I don’t think I’d be complaining if I got 350 mpg or 325 mpg from my car!
I’m assuming when you refer to 350mpg you actually mean you had an indicated range of 350 miles at the start of your journey and a 325 mile range at the end of your journey.
IMHO I doubt there’s a
problem with your car. The ‘range’ function (estimated miles that can be driven on the fuel remaining in the tank) isn’t a particularly useful - or accurate - means of measuring a car’s fuel consumption, nor is it realistic to judge a car’s fuel consumption on a single short journey whatever method of measuring fuel consumption is used. The only time I’ve used ‘remaining range’ in my car is if I‘m in an unfamiliar area and need fuel and I’m unsure of where the nearest filling station is; in that scenario, range will give me a rough idea of how many miles I can travel before I need to find somewhere to refuel.
The 15 minute journey you refer to in your post at an average speed of 20mph probably means a journey distance of between 5 and 10 miles and if starting out with a cold engine, your car’s engine will take much of that journey time / distance to reach optimum operating temperature. During that engine warm up period, fuel consumption will be poor and not a good indicator of long term average fuel consumption. Town driving also results in poor fuel consumption, with potentially lots of stop start work, braking and gear changes, and for much of the time the car‘s transmission isn‘t in the most fuel efficient gear. Also, if your car is brand new, the engine will be tight; as it loosens up with more use and you cover more miles, it should have a positive impact on your fuel consumption.
I would suggest you don’t bother reviewing your fuel consumption over individual short journeys as it isn’t a good indicator of long term position. Much better - and more accurate - to either;
- calculate your long term fuel consumption manually over a full tank of fuel or a number of tankfuls of fuel, based on the number of miles travelled since last tank fill up and the volume of fuel it takes to fill the tank.
or
- use your car’s fuel computer (the long term fuel consumption option) which should give a reasonably accurate view of mpg; probably within +/- 0-5% of the true mpg figure. Note that most - if not all - VAG fuel computers automatically reset the fuel consumption data back to zero after 100 hours of driving time.
