Fuel Economy

[Top Secret 2]

Hey guys, new here.

I own a '92 E36 325i, quite a nice thing it is too. I've owned it for 2 weeks, and deemed it would be a worthy replacement for my fuel guzzling Legacy.

Oh boy was I wrong!!

420km from a 60 litre tank of 98 octane is enough to make a grown man cry.. and in my case as a poor student question driving altogether!

Is this economy abnormal? Or is it to be expected?

Is there anything I can do to get more km out of it, besides for driving slower which I've already tried - still shocking economy.

Any help would be appreciated.

Cheers

[Andrew 30]

Welcome -

I guess your doing mainly around town driving - which sounds about right. I get 490 kms from my 323i (same size engine - granted a bit newer). 700 odd kms on the open road.

Could check for fault codes, fuel filter all the usual service issues.

[Top Secret 2]

Where would I check for fault codes? BMW Dealer? They'd sting for costs though!

Would it be beneficial to run any additives like injector cleaners through it?

I'd only bother changing the fuel filters etc. if I knew it was going to have a big effect on economy.

Cheers

[jochen 4]

420km from a 60 litre tank of 98 octane is enough to make a grown man cry.. and in my case as a poor student question driving altogether!

using 60L to drive 420km = 14.3L/100km

I achieve the same economy with my 4.4L V8 :-)

You'd expect around <9L/100km from a 6 cylinder engine of 2 to 2.5L size.

Which makes >666km per 60L tank

I saw a 3.0L E39 wagen which was averaging 8.6L/100km today.

8.6L/100km = 700km from a 60L tank

Of course, your engine tune might be perfect, and you may just have a very heavy right foot.

In which case, if you drove my car, you'd use 30L per 100km !!!

[Andrew 30]

When I had the E39 528 I was getting 10.5/100 k with the same driving. (City)

The e36 is a pig on gas.

[my_e36 43]

My 323i is a bit better, when I first bought the car, it does around 430-450 around town per tank of 98. Since then I changed the tyres from 225/50/16 to 205/55/16, K&N panel filter, 1 fuel injector cleaner per month and always use 98 fuel. Then it does around 480-500km mostly town and close to 600km on open road. Typical Auckland peak traffic.

[bezzal 1]

Is that 420km's froim 60l or is it just geting to the orange light?

My 535is does about the same around town, 60l = 420-450k's..

[Top Secret 2]

It's COMPLETELY empty on 420km. As in I ran out of fuel at the intersection in peak hour haha. Damn those accurate fuel gauges.

Well my car has 18 inch rims and 226000km, and a slight misfire so I guess that does contribute to it being thirsty.

So what would you guys recommend I do to it in order to get better fuel economy. It's a sad thing when you throw in $20 and the next day it's gone

[my_e36 43]

As in I ran out of fuel at the intersection in peak hour haha. Damn those accurate fuel gauges.

Hope you didn't get a ticket for that. Knowingly run out of fuel on the road can be fined.

[jpp 0]

Hope you didn't get a ticket for that. Knowingly run out of fuel on the road can be fined.

What else is funny is you can lose your drivers licence when riding a bike home intoxicated ;D!

[jochen 4]

Well my car has ... a slight misfire so I guess that does contribute to it being thirsty.

So what would you guys recommend I do to it in order to get better fuel economy.

Fix the misfire first and foremost.

Something is not right with your engine, get it properly serviced and tuned.

At the very least, new air filter and spark plugs - use the proper type for your car.

Check for no air leaks in any of the vacuum lines.

Check for proper compression on each and every cylinder.

Check that all the emission control systems are working and clean, you may need to clean your ICV (idle control valve), ECV (emission control valve), PCV (positive crankcase venitlation valve) if you have them. Use carburetor cleaner.

Once your engine is running right, then check your fuel consumption again.

If still low, consider a new oxygen sensor - if they are old, consumption can go up, due to aging chemicals in the O2 sensor.

All of the above is generic for any engine - most will apply to yours.

J.

[Yuen 16]

It's COMPLETELY empty on 420km. As in I ran out of fuel at the intersection in peak hour haha. Damn those accurate fuel gauges.

Well my car has 18 inch rims and 226000km, and a slight misfire so I guess that does contribute to it being thirsty.

So what would you guys recommend I do to it in order to get better fuel economy. It's a sad thing when you throw in $20 and the next day it's gone

Ditch the 18"s and go back to 15"s. It will be a noticeable difference. Going from 15" to 17" I lost about 0.5km/L. FWIW that was in a 320i but I am sure you will get increased mileage from going to 15"s. Make sure your tires are inflated properly, alignment is correct.

Also do what Jochen said, get a full tune up basically, pull your spark plugs and check their condition, check that ICV is clean, make sure all breather hoses are still in good condition (if they haven't been replaced, they will have rotten and probably broken off at 200,000km). Get your codes read for any possible errors - the oxygen sensor is a common one.

[MattA 162]

Sell it buy a V8 stomp on the right pedal 2 - 3 times daily the feeling will compensate any fuel consumption worries.....