my 2001 456mgt mileage is pathetic

Ross, I get way, way better than that. Do you have a hole in your tank??

 

6 miles per liter isnt bad. or didnt you mean that? I'll take it off your hands for only a small fee.

 

First buy XOM.

Then drive.

Dale

 

MPG = Miles Per Gallon. If it was only liters, he wouldn't be complaining

 

This could simply be one or two bad lambda sensors, or a case of one or more bad intake gaskets (leaning out the mixture on one or more cylinders, causing the computers to enrich).

20mpg for a TR? That's good. Could be true though, I believe I once found information quoting the 2.7 Motronic 456's to be better in this regard over the 5.1. Perhaps in those early days Ferrari could get away with more playing of the numbers, I don't know. It did make at least 20% difference though (like 33L/100km city for the 5.1 versus 24 for the 2.7). I found the 33 figure outrageous, but perhaps not so?

 

Ross- I hope that is US mpg and not UK mpg or that is really bad. You said you are due for a major service, so there is at least one thing to do not on the list. Know you will have the spark plugs changed, so consider using equivalent Bosch Platinums or NGKs instead of the recommended Champion A59GC. The thing not on the list is to have your injectors rebuilt. Not sure what it costs in Europe, but it is only about $20 per injector here. For some reason they seem to wear fairly quickly and that can affect both cold start and fuel efficiency.

Taz
Terry Phillips

 

Yes a few more things - if the intake has not been off for a while I'd highly recommend it, since it's hard to see whether there's an air leak there. Doing so also makes accessing the valve covers a lot easier, so when done as part of a large service (including belts and cam oil seals), it will not add hours to the bill.
There are only benefits to remove the intake with a large service; it allows the hoses in the 'valley' to be replaced if not done already. There is always crud around the injector holes, you might risk having falling that into the intake if the injectors are removed with the intake still on the engine. Have the injector seals replaced with the Viton ones from Mr Injector.co.uk and ask for the intake gaskets to be updated to the later type.

Have them check the spark plug leads, there was a recall for them once. Also the plugs on the wires closest to the exhaust (coil pack side) get cooked internally from exhaust heat, with outside rubber looking fine, inside insulator totally burned. Last, check the fuel pressure regulators (these can leak, you can also check them easily yourself by taking off the vacuum hose on them with a running engine).

 

Ross- Your regular mechanic should be able to handle all those issues. An SD2 readout after he is finished might be worthwhile just to make sure nothing is loose. While she is down is the perfect time for replacing the plenum hoses with Scuderia Rampante Innovations silicone hoses and also consider getting Dave's gold connector kit to make sure all the electrons get to the correct spots. Doing so will eliminate any spurious CELs, etc.

Taz
Terry Phillips

 

Terry; Didn't you mean the 128 oz gallon in the USA vs. the 160 oz gallon in the UK? 6 miles for a UK gallon is only 4.8 miles for a USA gallon- right?

 

Erik- That is correct, and that is why I said if that was UK mpg, it was really poor. Our pint is 16 oz and theirs is 20 oz and it scales from there, like you noted. The Brits bought their gasoline in liters last time I was there. I think that started when the old analog pumps could not get the price high enough to cover an Imperial Gallon of gas, so they switched to liters. Not an issue with the new pumps, but now nobody probably wants to know how much a gallon actually costs.

British pint is a better deal for beer, though.

Taz
Terry Phillips

 

My owners manual suggest an average of 22.24mpg @ 75mph and 22.35mpg @ 56mph while urban circle is at 9.5mpg

Never measured it properly but I think I average about 300-330miles from a full tank which would imply 13-14mpg

By the way mine is 456 GT

 

I did a great trip this weekend to Goodwood and London. 80% highway, rest country roads and a hellish rush hour (or perhaps just hellish by my standards) through London on Saturday aft that took hours. Some speed involved including long stretches of 140+ but no sound barriers were hit. 1250km and an estimated 200 litres for the entire trip (456GT).

It was a bit of a test drive, having just been serviced and this was the first long stretch for it for a long time, it had only covered a few miles in the past 5 years.
Car was happy with the exercise with its mood improving along the way and so was mine.

 

That is a very respectable 16 liters / 100km all including the traffic part.
Mine, a 2000 M, usually runs at that when not too much city traffic is involved. In city (I use it whenever I need to drive and that involves quite a lot of city errands but I just use every possible excuse to get it out) I get closer to 25.
Seen the type of car, the size of the engine and its performance, I'm not complaining ;-)

 

just filled up my 1999 MGT manual - 521Km - 89 litres = 17,08l/100km. Mixed use, Autobahn, in town, country roads.
not bad

 

Ross, thanks for the feedback on your fuel consumption issue, sounds like the intake gaskets caused you the consumption trouble. Was the idle elevated on your car before this fix, and is it now around 900-950? Did they check the lambda sensors as well?

Nice of you to borrow your Ferrari to your parents - mine can only dream of that… but then, I only have one Ferrari

 

gas mileage, price !

honestly, I haven't a clue as to mileage or what the pumps final tally is...matter of fact they could have charged me a quadrillion $$$ and I wouldn't have the faintest clue.

Just found my window sticker yesterday and wife points out 10/13mpg. Hmmm...all I know is I have to get out to pump my own gas: CA