My average mpg in london is 46, this is not impressive at all and it's near impossible to drive in heavy moving traffic with economy in mind i do try however but every so often it gets booted more than i want to. (This is with the car fully loaded in the boot)
1. When it comes to mpg it is important to note that no two engines will produce the exact same figure, the tiniest of variation in the build process will affect the on road performance.
FOCA - Modern cars are made to fine tolerances, and the same model leaves the factory, essentially, identical (apart from optional extras etc) higher milage cars (of the same model) can differ significantly, depending on use/ servicing etc
2. Weight makes a huge difference, i have a full size steal spare tyre (Sucks) getting rid of the extra weight is a must, get your "No fat chicks" stickers prepped.
Agreed, especially round town or accelerating/ decelerating or uphill, at a steady speed on the flat, not so much
3. Extras, some of us will have extras on our cars that adds massive amount of weights, like heated seats! heated seats or electric adjust seats are very heavy! The extra wire looms and what not that the titanium have that aren't use adds weight.
FOCA - Agreed, in general, its not what you might expect, though, door skins are negligable, full size 5-stud spare / jack = 20kgs any load on the electrics (anything heated is a big load, seats, windscreen etc) the heaters in the seats are light,as are the wires, but are a high electrical load, this puts a bigger load on the alternator, increasing mechanical drag the motor and mech for raising/ lowering the drivers seat only weighs 1kg
4. Runnings electrical equipment, this goes without saying... AC will lower mpg we all know this, but so does the blower, headlights and pumping stereo, put all of these together and you may find despite of your careful driving you can never achieve your ideal mpg. (Whenever talking about AC, do not open your windows and turn off the AC on the motorway, this creates drag that kills your mpg. Use AC at high speed and close your windows, the higher revs and speed will aid to AC to use less power)
FOCA - Agreed about the electrical loads but you must know what uses a lot, and what uses a little - (some electrical items use 10 times as much as others). as above, any electrical loads are eventually drawn from engine power via the alternator. In independant tests, open windows (even fully open) made very little difference at low or high speed, at a high steady speed, the AC hardly affected the MPG, accelerating/ rownd town, the AC had a big negative effect on MPG
5. Service service service. you can never over service a car.
FOCA - agreed!
6. Fuel types. Now this will always trigger strong opinions but here is mine. Shell fuel kicks @ss, forget anything else, shell fuel is no gimmicky marketing crap it really does increase your mpg over other fuels try it for your self.
FOCA Lets not go there! why? the cheapest fuel you can get might be the cheapest to run too
7. Get your self a shell fuel card. It's simple, once you have your card you swipe on each fill up, end of. shell sends you vouchers in the post, next fill up you swipe your card and voucher, instant money off, there is no BS waiting around there is no jumping through hoops or calling some strange 0845 number to claim your discount. Money is simply minus from the fuel on the spot, last time my £60 fill up was £45 using vouchers.
Since i am self employed and calculate my mileage and fuel cost for tax purposes, i can tell you it makes a huge difference regardless of how crappy your mpg is.
FOCA - You probably pay more in the long run
8. As others have said, tyre pressure is very important. Low resistant tyres are also a must on your next tyre shopping list, forget the budget tyre or something from your local kwik fit, invest in some performance low resistant tyres it's money well spent. Get your tyres well balanced and tracked. From experience i find this to be something that goes a miss very easily. Ford does free tracking!
FOCA - Low rolling resistance "economy"/ "eco" tyres are one thing (yes they can make a significant difference to MPG) they don't have a lot of grip though grip = drag (you can get them with a good compromise MPG vs grip). "performance" tyres are a tottaly different thing - made for wet/ dry grip performance - not for economy - i always ran very high pressures (38-41PSI) i like the "feel" and i thought it would make a big difference to MPG - in an independant test, low or high tyre pressures did not make a significant difference to MPG - the tyres may have had a stiff sidewall though (tyres with softer sidewalls may have produced mor drag/ less MPG )
Lighter wheels and narrower tyres can make a big improvement to MPG - some cars have two sets of official MPG figures depending on the size/ width of wheel/ tyre fitted, on most modern cars the wheels are too wide for the power (eg small engined Fucuses or Fiestas with big, wide wheels/ tyres) fitted for "looks"
9. Get rid of your roof rack if you have one of course. i know it can be hard to gather the effort to do so especially when some roof racks are fiddly. Handle your biz like a man.
FOCA - I always thought this too (i got rid of my rack/s) - the modern "aero" racks/ roof containers don't seem to make that much of an impact on MPG, though apparently.
10. I don't have one :- )
FOCA - Driving style - choosing your route carefully/ when you drive, eg avoiding traffic etc (if possible ) hypermiling techniques knowledge- can make a big difference