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-   -   What is the average MPG of you 87 535 is (http://www.bimmerfest.com/forums/showthread.php?t=288286)

HARRISON DOUG 05-28-2008 05:10 AM

What is the average MPG of you 87 535 is
 
i recently picked up a 1987 535 is straight 6 cyl...ive had only a short time, and noticed that im only getting about 15 mpg..im wondering is that about normal or should i be getting better mileage, if anyone could help that would be great..thanks

jimoreno 05-29-2008 01:20 PM

That is not normal. My '86 535i is currently giving me 21.0 MPG as reported by the OBC since I'm too lazy to write down mileage and fuel amount when I fill up. You are running rich which could be due to a bad thermo-time switch (about $40), a leaking cold start valve (about $50) or a very badly tuned motor. If this is the case you WILL destroy your catalitic converter so fix ASAP! You mentioned that you just recently picked it up, have you done a tune-up on it? This means, at least for me, replacing all filters (fuel, air, oil), oil change, spark plugs (use the correct ones, DO NOT use platinums!) and also the ignition cap and rotor. Depending on mileage and condition I might even change the spark plug wires (DO NOT use Bosch here!). Also make sure that there are no vacuum leaks by looking at all the small hoses and the inlet elbow (they tend to crack with age).
After you have done all this, adjust the valves and see how it feels. If you still have bad economy it might even be bad injectors.
How does the engine feel when idling and pulling? If you are planning on keeping it, get a Bentley so you can fix it yourself.

Good Luck!

Narbeh07 05-29-2008 02:32 PM

Hey, I have a 1986 535i auto. my car is getting around 18 mpg . its horrible i fill up gas every 3 days and with these gas prices i filled up 65 bucks the other day -_- i do not know how to fix this problem..My dad told me its because i punch it a lot but Ive been driving low rpms and not going over 45 and still getting the same results.. I kno im no help but atleast you know your not the only one out their with that problem.

jimoreno 05-30-2008 06:59 AM

I hope that you are not putting any premium gas. These engines are designed to run on regular 87 octane fuel. The only time that you might need higher octane fuel is if you have replaced the computer chip that advances the timing in order to get more power out of it; if you don't you are just wasting money. Just make sure that you use good brand gasoline (Top Tier) and not ethanol blends. Keep in mind that these are 20 plus year old engines with really old engine control computers without knock sensors and the like.

Regards,

hugh1850 06-19-2008 08:10 AM

Quote:

Originally Posted by jimoreno (Post 3288871)
That is not normal. My '86 535i is currently giving me 21.0 MPG as reported by the OBC since I'm too lazy to write down mileage and fuel amount when I fill up. You are running rich which could be due to a bad thermo-time switch (about $40), a leaking cold start valve (about $50) or a very badly tuned motor. If this is the case you WILL destroy your catalitic converter so fix ASAP! You mentioned that you just recently picked it up, have you done a tune-up on it? This means, at least for me, replacing all filters (fuel, air, oil), oil change, spark plugs (use the correct ones, DO NOT use platinums!) and also the ignition cap and rotor. Depending on mileage and condition I might even change the spark plug wires (DO NOT use Bosch here!). Also make sure that there are no vacuum leaks by looking at all the small hoses and the inlet elbow (they tend to crack with age).
After you have done all this, adjust the valves and see how it feels. If you still have bad economy it might even be bad injectors.
How does the engine feel when idling and pulling? If you are planning on keeping it, get a Bentley so you can fix it yourself.

Good Luck!

The OBC is notorious for reading high. If yours is reading 21 w/ mixed driving I'm willing to bet that your true mpg is closer to 17-18 range. I get around 15-16 mostly city driving as calculated by miles driven and gallons burned at fill up. My OBC says I get a little over 18.5 mpg.

323ivabeach 06-22-2008 07:35 AM

Quote:

Originally Posted by jimoreno (Post 3290740)
I hope that you are not putting any premium gas. These engines are designed to run on regular 87 octane fuel. The only time that you might need higher octane fuel is if you have replaced the computer chip that advances the timing in order to get more power out of it; if you don't you are just wasting money. Just make sure that you use good brand gasoline (Top Tier) and not ethanol blends. Keep in mind that these are 20 plus year old engines with really old engine control computers without knock sensors and the like.

Regards,

This is true, as I noticed I was getting worse mpg from premium the one time I filled up with it. My 1986 528e with 342k miles on it still gets about 24 mpg on regular.

HARRISON DOUG 07-02-2008 09:53 AM

Thanks For The Help Whent Thro And Found A Vacuum Port Under The T-body Open Looked A Round And Foudn A Line Put It On And The Mpg's Went Up To 20 On The Obc Went And Replaced All The Vacuum Lines Then The Trans Stop Shifting Weel I Got The Mgs Up For Just A Bit And Thanks Agane For The Tips

Lorrayne 07-18-2008 08:28 PM

About 21.

slowride535 08-21-2008 05:50 AM

Im getting 21~22mpg with mixed driving and 87oct. on my 86 535i auto trans.

I like to run a can of Seafoam through the sys. about every oil change.

dinanm3atl 08-22-2008 09:54 PM

I am getting mid to high 20's. All highway. Auto 535i. Running Premium.

banjerman 10-03-2008 07:04 PM

acetone
 
any one ever mix actone in thier gas
banjerman

Slaytanic_666 10-05-2008 01:26 AM

84 528e milage
 
Well without a full tune up still need plugs and a clean K&N and a new O2 sensor. I'm averaging about 30 mpg city and 40+ hwy:thumbup:

BTW running regular octane 87

dinanm3atl 10-05-2008 06:11 PM

Very nice!

But this is a thread for 535i :)

Slaytanic_666 10-05-2008 07:54 PM

Ooooops my bad
 
Sorry new to this forum. :angel:

dinanm3atl 10-05-2008 09:39 PM

That's ok!

At least you are getting some decent mileage ;)

\/\/hi+e }8oy 03-09-2009 08:16 AM

Quote:

Originally Posted by slowride535 (Post 3486960)
Im getting 21~22mpg with mixed driving and 87oct. on my 86 535i auto trans.

I like to run a can of Seafoam through the sys. about every oil change.

I was wondering the same things!!!!!!!!

ramelloh 03-22-2010 12:22 PM

87 535is mpg
 
Hey folks,

I am a new member as of today, but I have a lot of experience with mpg and many other things in the '87 535is 5spd, chipped.

I purchased my ride in 1999 with 65,371 miles and a bad cam for $4300.

After bringing everything back to spec and installing a Bavarian chip, the original engine got 21 to 24 mpg winter and 24 to 28 mpg summer, year after year. If I high miled it, a lot of coasting, it would easily reach 28mpg in summer, by my manual calculation. I find my rally computer is fairly accurate as well.

The gentleman from Canada must be talking Imperial gallons. 30/40 mpg? Not possible in US gallons in this car.

Sadly, my original engine went south, I believe due to a mechanic's failure, back when, to blow the oil out of the head bolt holes when replacing the head. Probably the same guy who crushed the cam oiling tube putting the valve cover back on and launched half the cam, long before I bought this ride. We found multiple hydrofracs around multiple head bolt holes in the block. Naturally, I started getting oil in my coolant a few years down the road. It took time to discover, because it was always oil to water and not the other way around, and just a little bit. It got worse over time. I finally admitted to myself that the coolant was getting too funky and I would have to treat the problem.

My mechanic could not find an '87 3.4 liter, so he grafted a '90 3.4 liter bottom end to my original top end. I got the bigger intake manifold and exhaust ports of the '90 engine and retained the fuel/air management of the '87. The '90 top end and air intake would not fit under the hood. There were motor mount mods involved as well. Other than that, everything pretty much fit right together including the updated original air conditioning system, original alternator and steering pump.

Sadly, the '90/'87 hybrid engine uses a bit more fuel. Magically, the older, '87 fuel/air management system is happy to deliver all the gas and air the freer breathing '90 bottom end desires. I have much more power, possibly as much or more than the '90 engine originally delivered, which was 26 more hp than the '87 E28 plant. 208 hp for the former and 182 hp for the latter. You see, the chip, matched to the '87 top end and computer, is still in place. All I know for sure is that my mechanic is very proud of his work and loves to drive this car and he has an M5. I call it scary fast.

I am currently getting 18.5 to 21 mpg in winter and 22 to 24 mpg in summer. I used to boast of my mpg, but now, no can do. Whadyawant ? It's a high performance touring sedan with four doors, a big trunk and a nice back seat. There is definitely a payoff in the improved torque and accelleration.

My original owner's manual says that I will damage this engine if I don't use premium fuel. I use it. I also clean out the engine regularly with a high quality top end cleaner, These engines are prone to getting fouled. They are sensitive to water, so keep after the dry gas during big day/night temperature and humidity changes in fall and spring. It must rain in that gas tank. Keep the fouling down and the mpg goes up. Try a valve adjustment per the manual's reccommended interval. That helps a lot.

My owner's manual also assures me that this car, in original dressing, will do 135 mph in fifth gear. It's right in the manual. I love that.

I currently have a serious problem with my 535is which I will discuss in a new post which I will entitle: "Solutions for repair of rear subframe bushing mount points for the '87 E28?". I and my experienced mechanic will be looking for any help we can get.

Regards to all,

Rick Melloh


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