E30 consuming way lot of fuel - driving habit?

[stormhunt3r]

My fc is quite good for highway driving (110-120kmh) but if i drive around 150-160kmh, the fc is quite bad..not really revving the engine though. And there's fuel smell coming into the engine..But i notice that for city driving, it's even worst..So, would like some feedbacks on how you guys drive ur E30. Btw, mine is 323i..Could it be the fuel mixture problem or my problem..I normally drive below 2k rpm for city driving and from what i observe, i could be dragging the car around in that rpm and thus cause the extra fuel consumption. Any opinion?What rpm do you guys normally maintain for city driving and highway driving, and how do you find the fc for your car?pls shed some lights here..tqcheers

 

[python_dev]

I had 2 issues along that line with bad fuel consumption (Well actually 3 but don't count my Heavy foot )
1.) Leak at fuel filter (Fix replaced rubber fuel hoses)
2.) Leak in Fuel pump O ring (replaced O ring).

 

[jarance]

bro... any indication of what is your present FC for various driving condition.

By stating "high or low or not bad FC" is quite difficult to judge or comment.

 

[berserkdroid]

Getting the smell of fuel is never a good sign. As Python suggested, look for leaks.

Had the same problem before and traced it to a leaking injector "o"-ring.

 

[Hachiroku]

bro... pls defined how much your full tank 60 litre can last for ?? km in town and ?? km for outstation drive... else what is ur ?? litre per km. various types of drivin style gives u much different mileage u get.

 

[stormhunt3r]

ok guys, for highway driving is 23.4 liters - 339km (110-120kmh / around 2-2.5k rpm)

as for city driving, 50 liters - 350-400km (around 2k rpm)
as for mix dirving, 50 liters - 445km (also around 2k rpm)

The fuel smell is very strong, as if it's in the cabin after i rev the car around 4.5-5k rpm (before i did my floorboard)
After i did my floorboard, didn't smell any fuel in the cabin anymore..

Besides, during idling, when i squat near the exhaust, the fume that comes out from the exhaust carries fuel smell..Is it normal?

ok..how bout driving the car at higher rpm, what's the fc of ur car?

for eg, if you maintain at 160kmh all the way for highway driving and as for city driving, maintaining at 2.5-3k rpm..

is it juz me being over worried of the fc of my car or is there someone else out there who is also interested to know more?

cheers

 

[jarance]

I also used to have high fuel consumption as well after doing up everything I can think of. Finally, the culprit for the high consumption was :-

1. Fuel was leaking at the hose where the level sensor is located.
2. Locking cap for level sensor was not secure tightly.
3. Hose clip was loose in the engine compartment near the inlet of the fuel rail. this problem is hard to locate unless you know what to look for.

FYI, the problems above are three seperate cases which took me sometime to determine when my fuel consumption start to increase over a duration of usage.

I think your problem for the high consumption is leaking petrol... Just follow your nose....

 

[E28driver]

The way to properly check consumption is as follows:
1. Fill your fuel tank 1
2. Reset odometer and Drive
3. Fill fuel tank 2
4. Calculate km driven upon fill 2 and the amount of fuel filled in step 3

 

[stormhunt3r]

I also think petrol leak is the main problem..maybe due to the pressure when i rev the engine..the fuel indicator needle drop is noticeable after driving the car at 180-190kmh for a stretch of road say 20 km..compared to driving smoothly 110-120kmh

E28driver, that's the way i calculate my fc..as this i just owned this car, would monitor the fc and the behavior for some time so that i will know if something is wrong with the car is the future..

btw, do you guys mind stating a rough figure of your fuel consumption for city and highway driving and pls state the average speed or rpm..this could do me a lot of help for comparison..

tq

cheers

 

[jarance]

Petrol leak is definite your problem but it is not due to the pressure.

The fuel pump is designed to pressurise the fuel rail for the maximum possible usage by the fuel injector. Any access fuel is basically return to the tank via the pressure regulator. The pressure at the fuel is actually kept at a constant pressure by this pressure regulator.

Fuel consumption is greatly affected when you are going at higher speed/higher RPM. Optimum speed for best fuel consumption is about 90 to110 kmh..