BMW X1 Owner's Manual page 231

CAUTION
The use of poor-quality fuels may result in
harmful engine deposits or damage. Addition‐
ally, problems relating to drivability, starting and
stalling, especially under certain environmental
conditions such as high ambient temperature
and high altitude, may occur.
If drivability problems are encountered, we rec‐
ommend switching to a high quality gasoline
brand and a higher octane grade — AKI num‐
ber — for a few tank fills. To avoid harmful en‐
gine deposits, it is highly recommended to pur‐
chase gasoline from Top Tier retailers.
Failure to comply with these recommendations
may result in the need for unscheduled mainte‐
nance.
Recommended fuel grade
BMW recommends AKI 91.
Refuel with this gasoline to achieve the rated
performance and consumption values.
Minimum fuel grade
BMW recommends AKI 89.
If you use gasoline with this minimum AKI Rating,
the engine may produce knocking sounds when
starting at high external temperatures. This has
no effect on the engine life.
Online Edition for Part no. 01402631131 - X/19
Fuel
MOBILITY
231