[Prev][Next][Index][Thread]

Bryan Schuett <bschuett@domain.elided>

>From: Bryan Schuett <bschuett@domain.elided>
>Date: Sun, 15 Sep 1996 23:13:43 -0500
>Subject: [none]
>
>In response to Phil Marx  BMWCCA #6024:
>
>>Your 535i is designed and specified to run just fine on 87 octane =
>regular
>>unleaded gas.  IMO there is nothing to be gained by using premium over
>>brand name regular...........
>
>My experience with my 89' E34 535i is different:
>
>Using Amoco Gold, 93 Octane Ultimate Clear, I get the following mileage, =
>driving on a 62 degree F day, with wind less than 3 MPH, going 5 miles =
>in each direction on a flat, straight highway, with only me (180 pounds) =
>plus a full tank of fuel:
>
>MPH:    MPG:
>=3D=3D=3D=3D    =3D=3D=3D=3D
>55      31.8
>65      29.0
>75      25.3
>85      23.0
>
>By using Amoco 89 Octane, I get noticable performance degradation, a =
>hotter running engine and 2 - 3 MPG LESS on the above numbers.  Think =
>about WHY you drive a BMW when you choose your fuel.
>
>Bryan Schuett
>89' 535i - stock, 145,000 miles

Bryan,

Sounds like your information is coming off the trip computer. If so I doubt
you could recreate the results under the same circumstances back to back.
Can't answer for your running temp and performance differences other than
maybe yours is so carboned up you've increased compression or your station
is cutting you gas.  If you get those results on just 89 what's it like
with 87?  You probably don't want to try!  I know I get 27.5 mpg calculated
by miles and fuel (87 octane reg.) used on long trips at 75+ with my wife,
and 3 kids in the old E28 535iA w/ 190,000 miles and an untouched engine.
I doubt I'd crack 30mpg by using more octane in the fuel from what others
on this and the BMW motorcycle digest have written, with far greater
knowledge of the engineering of petroleum than I possess (zero).  But if it
works for you, great. My BMWs always perform better after a wash and a wax,
too.  The fact is BMWs fuel requirement for that car is 87 octane and that
was the original question.

- -Phil Marx  BMWCCA #6024