e30 m52 fuel usage

[brainzy]

guys help me out please iv got a e30 cab m52 lump and a full tank gives me approx 170-80 miles and thats motorway driving and not even booting it!! does that sound rite or is there something drastically wrong??

[pac1982]

when i had an E36 with that engine i used to get an average of 18mpg with a combination of fast and laid back driving, they are not that economical, unless driven like a pedo would past a school

[brainzy]

see this is the thing that baffles me my mate has a e39 tourer and on Saturday we drove from london to coventry (pulling an empty trailer) and back with a mk4golf on the back so we,r talking approx 220 miles round trip and he was still showing half tank, i have no visible leaks nor can i smell petrol so i cant understand where its all going,

[pac1982]

see this is the thing that baffles me my mate has a e39 tourer and on Saturday we drove from london to coventry (pulling an empty trailer) and back with a mk4golf on the back so we,r talking approx 220 miles round trip and he was still showing half tank, i have no visible leaks nor can i smell petrol so i cant understand where its all going,

the E30 will have a much smaller fuel tank, even a different gear box or diff can have a massive effect on MPG as can the condition of the engine recent service etc

[E30BeemerLad]

What size tank are you using

What gearbox and diff are you using?

[Quaser]

and most importantly, are you driving with the hood down?

[Chris_B86]

My E36 touring, M52 2.5, rarely goes above 2000rpm on my daily commute, and I see an average of 21-22mpg. Motorway driving I can see that increase a lot, but that's due to the auto box leaving it doing a shade over 2000rpm at 70mph.

[brainzy]

roofs down, 3.25 open diff and the 328 manual box the tank is standard was a 325 before so dont exactly know what size tank.

[Ajsingh]

My e36 328i does around 20-21mpg.. Around Milton keynes which is 70mph then roundabout and so on.... On a long run its good! Averages (according to OBC) 30-35mpg(depending what speed).. 70mph jus under 2k rpm. And its an auto. Most iv had out of a tank is 385 miles. Mainly motorway, some stop/start and some in MK around roundabouts. Thats when i was commuting to london and back

[DanThe]

MPG will always suffer on an auto, you should be getting low 20's round town and high 20's+ on mway runs, if your consistently getting under 20mpg there is a good chance something is wrong

Does the fuel tank have a joining pipe at the bottom between the two half's?

[brainzy]

not too sure dan, il have to check n see, where would you say to start diagnosing what could be causing this amount of fuel usage, like i said there aint no visible leaks or any smell of fuel.

[Morat]

brainzy, to get a decent read on this you need to brim the tank and reset the trip meter. Drive till the fuel light comes on and brim the tank again. Then you'll know how many miles are on the trip, and how many litres of fuel you burnt.
From that info we can calculate your actual MPG and go from there.

[Brianmoooore]

You could do with a diff. ratio a bit taller than 3.25 to get decent fuel consumption. 2.91 (ex. 525e) would help.