johnnysensi
Active Member
My mpg says 22.3 or 23.2 all the time regardless of motorway or b roads...I've got 20wheels stormers on ...I'm trying to get at least 30 mpg ...would a remapping get me this figure..and smaller wheels
I never bettered 25 odd mpg in my DSE.....
Remapping for economy will reduce engine output as Diesel output is a function of fuel input as air charge is constant.
To increase economy, reduce fuel input.....to increase power, increase fuel input.....simple principle....
Obviously there are factors that influence efficiency, like air filter cleanliness, blocked or gummed up EGR/Intercooler/induction hoses and manifold, blocked exhausts, Viscous Fan constantly running, tyre pressures, driving style etc etc....
Remapping for economy will reduce engine output as Diesel output is a function of fuel input as air charge is constant.
To increase economy, reduce fuel input.....to increase power, increase fuel input.....simple principle....
Obviously there are factors that influence efficiency, like air filter cleanliness, blocked or gummed up EGR/Intercooler/induction hoses and manifold, blocked exhausts, Viscous Fan constantly running, tyre pressures, driving style etc etc....
What size tyres do you have on your 20" wheels? MPG depends on how the car is driven and the roads it is driven on and how far each trip is. On a decent M way run i get 32/34 MPG mine is chipped. Normally around town up hill down dale 20/22 MPG. But if i gun it around town stop start short runs it will drop below 20 MPG. If you have it chipped and drive like a nun you may see a slight improvement because of the chips more linear MAP. If you use the extra power and torque you WILL use more fuel.
johnnysensi
Active Member
No matter if I drive like miss daisy or boot it ...never changes ...275 40 20 ...I think ..there low profile tyres ...can drive different ways and stays same mpg ...confused loool
Do you reset the computer when you fill up?
Bladerunner919
Active Member
Also, the computer may well not be accurate. Mine does a couple of miles more mpg than the trip computer indicates.
johnnysensi
Active Member
Thanking you ..
tomcat59alan
Well-Known Member
I'm showing 25.8 at the mo, lot of round town, have had 32.2 on a run (70 and a bit more on motorway/ A roads). Chipped by Superchip.
Bladerunner919
Active Member
Have you compared the displayed mpg with the actual? I thought I'd read that chipped cars tend to over calculate the mpg because there is more fuel going in that the car expects?I'm showing 25.8 at the mo, lot of round town, have had 32.2 on a run (70 and a bit more on motorway/ A roads). Chipped by Superchip.
The OPs car has tyres on his 20" wheels that send the wrong information back to the ECU. Speed is calculated as a mile = 8000 pulses from the ABS sensors. If the wheel and tyre have a smaller rolling radius it turns quicker for any given road speed and the 8000 pulses occur sooner. At an indicated 60 MPH the actual road speed is only 57.2 MPH. The fuel calculation is done by comparing fuel used and miles travelled. So if he put a gallon of fuel in and drove at an indicated 60 MPH for one hour then ran out of fuel. Theoretically his MPG should be 60. Were in actual fact he has only travelled 57.2 miles not 60. So he is only getting 57.2 MPG. This discrepancy cocks up the fuel computer. Just as it would if you had larger rolling radius wheels and tyres because they turn slower you would be going faster than indicated. Plus with smaller rolling radius's he is adding 2.8 more miles to his overall mileage than he needs to every 60 miles. You can't get that back.
