Bad Fuel Economy

someguy · Post by **someguy** » Thu Apr 16, 2009 4:11 pm

Hi Guys.

I had gone for a cruise down to the coast the other day and filled the tank completely.

At the end of the trip I had almost no fuel left in the tank and had only traveled 390km.

Is this normal for an EA82? I would have thought being 1.8l I would have got atleast 600km out a tank (Considering our 3.8l V6 BMW 528 gets 800k off a tank)

This is the first time since I have had the car that I have filled the tank completely (yes, Im tight but I am a student) so I was stunned to see how little I got off a full tank.

What could be causing this.

I know its not the send unit as I just installed a new one.

GOD · Post by **GOD** » Thu Apr 16, 2009 4:26 pm

when you say the tank was almost empty, are you going by the gauge or did you refill it? My car's gauge shows pretty close to empty after using about 25l/300km.

Dane.

someguy · Post by **someguy** » Thu Apr 16, 2009 4:41 pm

GOD wrote:when you say the tank was almost empty, are you going by the gauge or did you refill it? My car's gauge shows pretty close to empty after using about 25l/300km.

Dane.

I was curious so I took the send unit out and physically looked in there.

Was no more than a litre left in there

daveosubi · Post by **daveosubi** » Thu Apr 16, 2009 5:34 pm

I had roughly the same fuel usage, bit hard to tell with bigger wheels and driving in the hills alot. Also my fuel gauge is always a 1/4 under what really in there, I drove for about 130km on empty with a jerrycan for when it ran out testing it.

Generally all cars v8 or 4 cylinder get around 350-450 to a full tank with normal driving, they just have different capacities. You also normally get much a better mileage % increase with big motors on long highway runs that with smaller motors.

Suby Wan Kenobi · Post by **Suby Wan Kenobi** » Thu Apr 16, 2009 7:38 pm

With your EA82 running properly it should get 600kms on a cruise drive assuming you havent got larger wheels or a lift kit. My L RX turbo gets around 7.8 - 8 L/100 when on a long drive.

That said you may need to set the ignition timing, and maybe give the carby a clean out as well as making sure your aircleaner is actually clean. With the high Ks compression could also be down a bit which will use more fuel.

AlpineRaven · Post by **AlpineRaven** » Thu Apr 16, 2009 8:26 pm

How many litres did you put in and you would be able to work out kms per litre...
Cheers
AP

subasurf · Post by **subasurf** » Fri Apr 17, 2009 1:18 am

Yeah, top her up, drive an exact distance then fill her up and tell us how much fuel it used.

ChPLAT · Post by **ChPLAT** » Fri Apr 17, 2009 11:57 am

My ea81 went exactly 445.6 k's on a full tank. I know this cus I ran out of petrol the freeway the other day.

steptoe · Post by **steptoe** » Fri Apr 17, 2009 1:59 pm

I got 609km to my 60litre? tank in a totally rebuilt/refurbished/reconditioned EA81 Brumby run to stop to test distance gain over old engine and tune. never refilled , went to lpg

Roughly got 545km to 53litres of my supposed 55 litre tank in efi L series sedan with turbo, 3 speed auto. Gauge hit empty mark at about 300km. Oddly enough with gauge now matched to LPG sender unit still hit E at about 300km as an auto, convert to 5 speed manual and new valve springs takes until 390 - 400 to hit the empty mark now. Theoretically gained another 100km on top of the 500km range I had before convert to manual

Student? tight? That is how you can afford the BMW as well ? Mark out a 10km run precisely based on the BMW odometer and check that against your subaru odo?

is/was the choke stuck on for too long?

BMW were never afraid of fitting big capacity tanks in their cars.

someguy · Post by **someguy** » Fri Apr 17, 2009 2:34 pm

steptoe wrote: Student? tight? That is how you can afford the BMW as well ?

Parents BMW

BMW were never afraid of fitting big capacity tanks in their cars.

that is true. the little old 89' Audi is only 2.3l and has an 80l tank.

I spose next time i have enough for another full tank I will try again

steptoe · Post by **steptoe** » Sat Apr 18, 2009 10:12 am

Yeh, you get the drift.

Look for black smoke out exhaust when you pump but not thrash accelerator to see any RICH indication of choke malfunction. Pull of air box to see choke blade is fully open as in vertical when at op temp. Smell of fuel? Climb under to see if any wetness around tank fill hose or supply lines.Fuel conditioner may help if it claims to clean your bits, or even buy some CRC carby cleaner and follow directions as it can clean out little air bleed jets etc in carby to help restore things if they were blocked or gunked up in first place

someguy · Post by **someguy** » Tue May 12, 2009 8:52 pm

sorry to bump an old thread.

Economy has gotten worse over the last month or so.

Worked it out.

Put 55l in the tank.

got 389km out of that which is 7.07l per 100k

Still doesn't seem quite right.

Its gone from a full tank getting me 550-600k ( 2008 ) to 390-400KM (2009)
thats a pretty shocking loss.

Im thinking I might have to pull the carby out and give it a good clean and also check the fuel/air mixture.

Anyone in SA wanna give me a hand as I am still learning my way around engines and have never done this before :P

steptoe · Post by **steptoe** » Wed May 13, 2009 12:32 am

calcs are not quite correct , or it's a typo

7.07 l per hundry.
you did 3.89 hundred km
without thinking, too hard , call it 400km

7.07 x 4 ( for the hundred) is about 28 litres. u used double that or near enough, so double 7.07
you got about 14.1 litres per hundred

GOD · Post by **GOD** » Wed May 13, 2009 2:13 am

You were right before the edit, someguy.

389 km / 55 l = 7.07 km/l.

Phizinza · Post by **Phizinza** » Wed May 13, 2009 11:31 am

Yeah, you have a km per litre figure there, no litre per 100km.

divide the litres used by the km with a moved decimal place

55 / 3.89
= 14.1 L per 100km

I would suggest looking for fuel leaks if the car still feels right when driving.

someguy · Post by **someguy** » Wed May 13, 2009 12:15 pm

Phizinza wrote:Yeah, you have a km per litre figure there, no litre per 100km.

divide the litres used by the km with a moved decimal place

55 / 3.89
= 14.1 L per 100km

I would suggest looking for fuel leaks if the car still feels right when driving.

I can't seem to find any leaks.

No puddles on the driveway or under the car either.

The car hasn't lost any power.

The only thing that has changed over the last month is the blowby (getting oil in the airbox) but thats apparently normal for the EA82 so that can't be it.

Hurray im getting the same economy as a 6.0l Chevrolet V8

Phizinza · Post by **Phizinza** » Wed May 13, 2009 1:32 pm

Do you have a new clean air filter? I've only ever personally seen oil in the airbox because the air filter was blocked. They are only like $11 so its worth a try. That will hurt your economy too.

Remember, petrol evaporates fast. It may not be dripping. But if you have a bad enough leak to cause the problem the pipe will look wet all the time.

someguy · Post by **someguy** » Wed May 13, 2009 5:02 pm

Phizinza wrote:Do you have a new clean air filter? I've only ever personally seen oil in the airbox because the air filter was blocked. They are only like $11 so its worth a try. That will hurt your economy too.

Remember, petrol evaporates fast. It may not be dripping. But if you have a bad enough leak to cause the problem the pipe will look wet all the time.

Well its not a fuel leak, gone extensively over the under side of the car while its been running and no leaks or dampness what so ever.

Im thinking its something more to do with the carby now.

I am smelling petrol in the cabin while I am driving around (maybe coming through the aircon vents?) (mmm high off fuel fumes)

Any thoughts?

Put 20l in last night and got a "whopping" 70KM out of that

ian059 · Post by **ian059** » Wed May 13, 2009 6:27 pm

someguy wrote:I can't seem to find any leaks.

Hurray im getting the same economy as a 6.0l Chevrolet V8

Not bad compared to my bosses AMG 6.3l Mercedes Benz at 20l/100km.
IanC

someguy · Post by **someguy** » Wed May 13, 2009 6:32 pm

ian059 wrote:Not bad compared to my bosses AMG 6.3l Mercedes Benz at 20l/100km.
IanC

Haha, thats crazy.

Not as bad as the bugatti Veyron or Ford GT that goes through a tank every 10 miles or so :P