[Diy_efi] newbie questions (m)

[Daniel R. Nicoson]

I'm surprised that you don't get a little better mileage with the 325.

I've got a 1998 528i with the 2.8L six.  On long highway trips I get 28-29
mpg and that's "leading the pack", not easy driving.  I get 25-26 with my
normal daily driving 22 miles each way to work, 50% hwy, 50% city.

I use 89 octane, $2 autolight spark plugs, completely stock car, BMW
synthetic engine oil.

I think these cars are pretty efficient already, don't really know how much
more you will be able to squeeze out.

What do you feel is possible?

I know tires are probably the biggest difference I have seen.  I loose a
good 2 mpg in the winter with my winter tires versus the summer tires.

Who burns chips for these cars?  Are you sure they will really get you
better mileage?  The factories really do a pretty good job of calibration.

I tune my 1994 Mustang GT electronically, full control with a TwEECer.  I'll
tell you fro experience there, its hard to beat the factory for overall
drivability.  I've heard a lot of complaints on discussion groups from
people that have bought chips from "experts".

Let us know what you come up with.

Dan Nicoson


> -----Original Message-----
> From: diy_efi-bounces at diy-efi.org [mailto:diy_efi-bounces at diy-efi.org]On
> Behalf Of R P Davis
> Sent: Friday, May 13, 2005 11:23 AM
> To: diy_efi at diy-efi.org
> Subject: [Diy_efi] newbie questions (m)
>
>
> I'm new to this board. I've been trolling for a few months now and
> have learned a few things. But I still have questions. I am more of a
> hobbyist trying to keep my car running and operating as inexpensively
> as possible. My goal is to increase the fuel economy of my new to me
> car.It is an 89 BMW 325iX w/215K miles inline 2.5 liter 6 cyl with
> bosch motronic 1.3 (last 3# on ecu = 173). When I got it I could get
> 22mpg highway and I run premium fuel.
>
> Is it someway possible to use a wide band O2 sensor in this
> application? Will I need to have a new chip burned for the ecu? I
> haven't searched the archives much but I did come across a 528e BMW
> (2.8/2.7 liter inline 6 efficient engine, had it in my last 325e) that
> someone had installed a wb02 into. I couldn't find anymore info other
> than it was installed.
>
> Any ideas? I can do basic soldering and wire maintenance. What will I
> need to make this work? Also, would a MAF be useful as well? Anybody
> have one that will work and is inexpensive? If not, I'll probably take
> the AFM which is larger off the m30 BMW engine and swap the
> electronics to make it work.
> Right now I'm running a K&N panel filter, Amsoil 75w90 gear lube in
> the front & rear, Amsoil ATF in the 5 speed transmission and in the
> transfer case. Once I replace a leaky valve cover gasket and leaky
> pressure relief on my oil cooler I'll convert the engine to Amsoil
> 10w30 motor oil and use a bypass filter to extend my drain to 25K
> miles. I also installed an ignitions solution plasma booster (multiple
> spark discharge device) and the car came with "high performance"
> spiral wound ignition wires from Bavarian Autosport. Without
> synthetics in the engine is getting 26mpg avg (80% highway, 20%
> stop&go city).
>
> Any recommendations on what I can do to get this car closer to 30 mpg
> would be great. I plan on keeping the car for at least 100K miles
> (3years or so with my driving habits). I've got 215/60-14 Cooper
> Cobra's (only tire i could find in that size) tires on it right now
> and my winter tire for Vermont is a 185/70-14" Nokian Hakka's. I know
> tire size plays a big role in fuel efficiency so I try to keep them
> with a small diameter.
>
>
> Thanks,
>
> ~ryan
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