actual vs mfa mpg

[DT1]

Am a bit confused by all this as.

Originally posted to see if any way to make the mfa mpg more closely match actual, whereas thread seems to have turned into how to make actual consumption match the mfa ! ( not quite the same )

Not sure what you mean, you asked,

What are other folk getting ? presume the MFA number is ornamental as seems more affected by weather / fuel brand

Any way to make the mfa more realistic ?

and people responded by saying that their MFA's pretty much matched real life calculations, i.e., that the MFA is realistic.

IIRC the vacuum tube to the back of the instrument cluster is involved in how the MPG is calculated by the MFA, so if yours isn't correct that is an easy first check to make.

[haddock_n_chips]

Im confused by this too

Your MFA's work??!!!! hahaha

mine used to work intermittently, now not at all, get clock, oil temp, time driving and outside temp but not MPG, guess the vacuum hose has come off or its fubar'd

not really bothered though and with the larger throttle body, maybe i don't want to know!?

[klittle]

I have a Mk2 GT but no MFA fitted, but doing it the old fashiod way of Litres vs total miles to tank & I'm getting roughly 36mpg. I'm running a DMTL downdraft Weber & considering my last car wouldn't go over 25mpg & the wifes does 18mpg on average I'm a happy Rocco driver. It certainly sounds like mid 30s is about right for the Mk2. That's using Super Unleaded too by the way.

[duggers]

MFA is always optimistic. Even the new ones lie, my Sharan TDI gives readings of 60mpg on a run, and i know its wrong!
The DX engine was essentially a bit of an upgrade on the original 1.6 Audi 80 GTE lump first shoehorned into the golf. So its a 70's design with mechanical injection very similar to the set up used on Me 109's !!!!
It will never be that economical so if you can get 35mpg average without trying too hard you are doing well. the MFA will in my experience be around 10% out in real world conditions.

[iroberts696]

Have now replaced white pressure sender and oil pump and mpg readings now a tad pessimististic but far more realistic than before. So guess oil over pressure throwing the mpg calculation off this would suggest folk getting high ( 40 to 50 ) mpg reading has engine oil over pressure probably due to the non function of the oil pump pressure relief valve.

Pity the high numbers were nice, but I did want realistic.