Talk Morgan Forums Morgan Sports Cars Classic Morgans (pre-CX) 4/4 fuel economy

I have owned my 4/4 (brand-new 2015 model with Sigma engine) for a year now and I like it very much. There was a problem with the brakes but I think that was just bad luck. Apart from that it has been entirely reliable. I just checked the fuel economy and it comes out at a bit over 35mpg (about 8 litres/100km).

I have hardly ever been stuck in traffic and rarely drive on roads with traffic lights, so I expect a lot of people will consider this to be dreadfully high consumption, but I am rather surprised and impressed!

I had a new Sport in 2009 and in 4 years and 24,000mls of spirited driving never got below 43mpg.

Stop putting spirits in your tank. Use petrol and tell us what your petrol mpg is!

Come on it's Haloween time .

Hi I have a 2009 4/4 Sport which has done 22k averaging 45+ mpg. On long runs up to 50mpg.

Eddie

I don't know how much spread is acceptable concerning the consumption of this engine. Because your 4/4 is so new, candidates like a blocked air filter can be ignored.
Only if you should use a K&N airfilter, micro oildrops may kill your even new MAF sensor with the consequence of wrong readings and probably a too high consumption. And an issue concerning the MAF sensor may not or very late be shown by the ECU.

Normally I would say, 8 litres is ok, but when you drive so smoothly without traffic lights in your way etc, it could be a little bit better.

My 2014 4/4 also had a consumption around 8 to 9 litres/100 km but under normal mixed conditions. It was just a tad too high.

A few things that Could influence the consumption:

On my engine, the lambda 1 sensor (before cat) had a too low voltage, it jumped between 0.5V (instead of 0.9) and 0.1V. This results in a too fat mix. It is easily to check when you (or your garage) have an advanced OBD2 reader which shows the "jumps" in real time in a graphic manner.

Especially this lambda 1 fault could be ignored for a too long time (months) by the ECU before finally the engine light will turn on. In my case the engine run much more willingly and powerful after I changed the lambda sensor 1. And the consumption went down to 7 to 8 litres which is very ok regarding my driving style.

If you are under warranty, let check everything concerning the possibility of wrong air. Intake wise as well as with regards to all connections - from the intake manifold sealing and exhaust system down to the lambda 1 sensor. Even the last connection between the main silencer and end pipe should be checked to give a good high revving behave (this endpipe connection has no influence on the consumption).

Check if the cat is working and not blocked for some reason. If any of all the sensors fails you could be switched into a "limp home" modus where all sensor inputs are ignored by the ECU, the variable camshaft is switched off and again, the mix is too fat, the power too low.
On older cars with two lambda sensors per bank, the one behind the cat only "read" values. On the newer engines the lambda 2 value after cat could influence the powerband of the car, if the value means a not proper working cat.

For little money I would change the coolant liquid sensor, because sometimes it sticks at some value of temperature for a too long time, sending wrong or much too slow following readings. This is just a try and error task but often described as a fault in Ford forums concerning this engine.

Whatever it is, I'm thinking the mix of your engine is too fat for some reason as otherwise it is a brand new.

My 2015 4/4 with cold air induction K@N filter Lybrands Manifold and Williams remap is on around 35 mpg . I'm very happy as with the remap the car now performs so much better even in 5th gear .
If you want high mpg get a turbo diesel my Volvo C30 does 53mpg .

that is a pretty good value of consumption as your car even produces significant more power than a regular one. My motivation for searching faults is not to check for the consumption as an end benefit. But if the consumption is "right" the engine runs normally much better.

My 2015 4/4 with 4k covered returns around 45mpg. The lowest i have managed is 43mpg and i do exercise the rev counter!

Never stops amazing me how far it goes between fill ups. There seems to be no penalty even if the performance is enjoyed. I guess lightweight is the key to it.

How many miles (sorry, I mean kilometres) have you done in that year Peter? Sigmas do loosen up very nicely and my mpg has improved year by year (and I will freely admit I don't use it enough, so for others this gradual improvement may not be so noticeable).