your mileage may vary....

My 456m gta gives me 14 or there abouts mixed driving,with not too much urban mileage.

 

you mention one of two things I never have noticed in my five years of owning a Ferrari: Gas mileage and gas costs....

have never looked

BUT, having said that, I noticed in the 456, that when the gas-needle gets below the 1/4 I had better start looking for a gas pump, which is why I always keep it above the 1/4 mark. can you imaging stranded in a beautiful car because ya' ran out of fuel? not fun.

 

...from mine.

Just checked the highway mpg from my recent trip to Montreal. I was so (pleasantly) surprised to see it...

Konstantinos

 

My 550 is about the same i think.

It's mainly to do with poor ECU that is so out of date for what caliber of cars we have. They are pretty much batch injection, so not necessary fuel is put int at the same time.

if you wanna fix that, you gotta get the Motec M800 or similar that does seq. Injection so only injects 1 at a time.

This resulted in that Saurus's V12 TT car about double the gas mileage, well that's not too bad, I can deal with that.

I have been contemplating to get that done, but mmmm. for nearly 10k dollar job, is it worth it ? hard to justify....

 

I get 8.5 mpg in my 2003 575. Hopefully I can it into the 7's soon. At this point it would mean I am having a bunch of fun with the car.

 

I am surprised to see that your average in France was 90mph, since the local speed limit on highways is 81 mph.
I just made a trip from Holland to the Riviera and back in my 456 MGT, and including stops for fuelling and coffee drinks and the unavoidable traffic jams, my average was 65mph.
I consumed between 17 and 18 mpg depending on how flat the countryside was.
I did not (dare to) measure how much the consumption was with town driving and shopping, but it must be something like 8 to 10 mpg.

 

Sequential injection is a little bit better than "all at the same time", but a factor 2 seems very unlikely.
Take as an example a 12 cyl engine running at an average of 3000rpm, meaning 18000 combustions per minute or 300 per second.
In a sequential system, this means that every 3.3 millisecond another injection cycle is starting
In a batch system the first cylinder receives its injection just in time, but the last cylinder receives it 17 msec to early.
Now how much petrol can evaporate in 17 msec, also implying that it would than be used by other cylinders since it cannot vanish.
If it was a significant amount, it would mean that the some cylinders would receive too much petrol and the last cylinders would always be too lean, sind all receive the same amount injected to start with.
But the effect of this all is only marginal in real life.

 

In my experience, it's not high speeds that are the mileage killers, but driving around town. Combined (30%city/70% highway), my GTA gets around 14. At a steady 75-80, it'll be around 19-20. I've never done a complete tank just driving around town, but I imagine that the sub-10 mpg you experience would be normal.

 

That's my experience as well, in the 456GT.

 

I just read this thread for some reason ... I have put about 10,000 miles on a 456M-GTA over the past year. I have the data for the most recent 8333 miles.

US MPG 14.81 with a Max/Min of 10.21/18.5

This is with more than quite a bit of motorway driving. YMMV

(I return to your previous programming)