MPG - awful

[jonybravo 0]

Not sure if this is in the right section (apologies if not)

 

This morning I was flicking throught the display options on the ECU, and I was surpirsed to see that I am averaging 18mpg!! :cuckoo:

 

Had a look at the stats for my model (2.0L 16V) and I'm told it should be around 30mpg. Now I know it's an old car (1994) but surely the MPG should be better

 

Anyone have any ideas as to why this might be? I am planning a road trip aroudn Europe in July, but don't fancy having to stop at every petrol station I pass due to such poor fuel economy

[Guest]

Was that the MFA 1 or 2 setting and regardless of which how many miles / average speed was that calculated over?

 

If MFA 1 what sort of journey had you just done and if MFA 2 what sort of journeys made up the total miles showing?

 

Commuting out of Bristol city centre in a VR, sat in heavy traffic for 30 mins doing 2 miles would give me 6MPG, by the time I had done another 5 miles in 15 mins I would be up to around 18MPG and doing that journey a few days with nothing in between would show awful figures in the MFA 2 setting.

But..... doodle down the motorway at 70mph for an hour (very hard work keeping behind a camper van!!) will show 30+ MPG.

 

I would say folks need to know what driving the display was calculated from before anyone could give you a more useful answer.

[andy 0]

Don't trust the MFA in the first instance. There is only one accurate way to measure MPG, distance travelled over fuel used. Fill the car up with fuel, reset the odometer or note the mileage, drive as normal. At some point thereafter, preferably at the end of the tank of fuel (better averaging), fill the car up again and divide your distance travelled by the fuel added. Only then will you know if the MFA is working accurately.

[jonybravo 0]

thanks for the posts, butterfly - yes your theory is probably correct, I used the Rado for the daily commute to work, no motorway miles, lots of traffic lights and standing still in traffic.

 

I'll try your suggestion as well Andy

 

thanks all

[Guest]

Obviously if you want to check the MPG using the 'fill her up, go for a drive' method make sure you do the sort of driving you would expect to do on your trip.

Can't think of a more wonderful way of spending a day than doing a 300, hopefully 400, mile road trip in a C you love. Look for somewhere you have never been 150+ miles away and make a day of it :)

[jonybravo 0]

"Look for somewhere you have never been 150+ miles away and make a day of it :)"

 

 

Ha ha yeah, hence the road trip round Europe idea, should be fun, just hope the old dear doesn't break down! :lol:

[Guest]

Would be a bit of a bugger setting off to Europe and after the first tank full realising your fuel cost calculations are way out. I suppose it depends on how careful you need to be with the costs.

 

I mean go for a day out road trip 150+ miles from home and back again to check what MPG you realy can expect. If it is too low you'll have a bit of time to investigate why. Unless you are off in the next day or two!

[davidwort 0]

In my experience the 16v MFA tends to underread at low speeds/stop start traffic but gets more accurate when more cruising is invloved, seems to be down to relying on inlet manifold vacuum readings to calculate MPG.

 

Things against you with the 16v:

low ratio gearbox

torque isn't great at low revs

K-jet/KE-jet injection is mechanical and no-where near as efficient as EFI

the corrado is heavy for it's size

slow engine to get to fully warmed up and warm up period can use a fair wedge of fuel on the K-jet system

 

other things that don't help:

tyres and tyre pressures

dirty oil filters

old K-jet injectors can perform badly on spray pattern

wheel alignment

ropey exhaust sytems

crap old gearbox oil

wrong spec plugs

timing (both ignition and engine - they often get set up one tooth out on a cambelt change)

vacuum leaks and dodgy ISV's

 

few things to go on :)

[jimmyvwjunkie 0]

good list there david. my mpg's are crap the now. so got myself an isv coming and new oil filter and so on all getting done this weekend. also getting tuned 2. just as your list states it basically means give your car a good service on a regular basis.

i never really thought the raddo was that heavy, well compared to modern cars weight.

[Jim 1]

I find mine is very fussy with fuel as well.. different fuels can give up to 3-4MPG difference on a long run. Strangely whenever I put higher octane fuel in, I end up returning worse MPG?!