Weird mpg readings on the trip computer.

[MoMartin]

Does anyone know why my trip computer will essentially reset the mpg after about 15 seconds of driving? it happens as soon as i set off, and no more, but what it does is reset or drop the mpg readings after the first 15 seconds of driving, it normally drops from about 15-23mpg down to about 6mpg when there has been no actual change in the driving style.

also it seems that accelerating slowely up to a certain speed rather than planting the foot to the floor up to the same certain speed seems to use more mpg, is this correct? because ive always been taught that driving slowly will help maintain fuel...

Cheers, Mo

[Nino]

Sounds to me that you have "live" reading mpg on rather than journey mpg. On your display does it have a little number 1 in the top right corner? If it doesn't then you have it on live reading. On the right hand stalk there should be a button. Press it up and down to cycle though the different options until you find the one with a little one in the top right corner. If you can only find one with a little 2 in the corner that is your av mpg for the tank. To set it to journey there will be a button marked "reset" underneath on the right hand stalk. Press it once and it will change to "1" 

Hope this helps

[MoMartin]

haha, i didn't make that mistake, there is a live mpg reading then an average trip reading, on the 1st tab right? well on the average mpg reading i can just be driving along, with it saying 23mpg, then all of a sudden it will drop to like 6mpg or something stupid, even when i haven't actually moved my foot on the throttle.

[rio_gti]

strange one that!!! not to hijack but mine plays up sometimes, if I press the button it wont change from 1-2 or reset, then it might reset shortly later, its like the button is broken!!! but the next trip it will be fine 

[MoMartin]

Thats what gets me, everything works perfectly (though i do sometimes believe that is shows less mpg than i am actually getting)

[mcgee9t2]

cant help with the trip etc.

but with regards to driving style, low revs is not always the most economical, if you go too low then there is too much strain on the engine with it wanting to stall so it will put more fuel in etc.

its like Jogging up a very steep hill compared to sprinting on flat ground. jogging takes up less energy but because your on a hill its harder because theres more pressure.

the best way iv found to get good mpg is not going under 1700ish rpm, and not going over 3000ish rpm, using that i usually get the best part of 40mpg (with a few boots up to the red line in there), and if i really try and get economical i can see over 40mpg  (well i can see it if i havent got bored and fallen asleep )

[MoMartin]

40mpg?! i get between 33 and 36 mpg on the motorway and about 20 to 25 mpg around countryside areas/ town areas

[Nino]

In that Case Change your coolent tempature sensor

[Dalo Harkin]

It will all depend on what the car has had done to it, engine condition, mileage and driving style all contribute to good / bad MPG

[MoMartin]

In that Case Change your coolent tempature sensor

how would that make a difference to mpg 

and that mpg is between 70 and 80, i do get 40+ mpg if im driving at 60