91 Wrong Fuel Dangerous or not

[kwhelan 233]

So I accidentally fueled up from empty with 91 on my 525 m54(usual garage was shut and Was in a daydream)

anyway drove 400k with 3 adults and luggage over probably biggest hills in North Island,Taupo Rd and didnt really notice any difference,perhaps a slightly lower km/l than usual 10.2 km/l for a trip and a slightly earlier kickdown when passing altho there were that many police, cameras and traffic around It was a slow trip anyway.

So does running on the lower fuel cause long term problems with tuning or something and if I just refill normally next time no damage done or what harm could I do by running on 91 all the time. The price difference adds up over a year and I suspect there's plenty of old bmws around where people happily ignorant fill them with 91 all the time.

[*Glenn* 854]

It won't hurt it. Just change back to your normal fuel..95 0r 98

Edited April 2, 2013 by *Glenn*

[Allanw 1052]

So I accidentally fueled up from empty with 91 on my 525 m54(usual garage was shut and Was in a daydream)

what harm could I do by running on 91 all the time. The price difference adds up over a year and I suspect there's plenty of old bmws around where people happily ignorant fill them with 91 all the time.

In addition to what GLenn said, in an M54, the extra fuel it uses will very likely cost MORE than the extra cost per litre.

It will be running retarded timing (and possibly alters the Vanos settings) to suit the lower octane.

[kwhelan 233]

In addition to what GLenn said, in an M54, the extra fuel it uses will very likely cost MORE than the extra cost per litre.

It will be running retarded timing (and possibly alters the Vanos settings) to suit the lower octane.

After running around town for a few days it just didnt feel right and after refueling today with the computer saying range--- what an immediate difference,just so much more pep cant believe how much better it runs on 95

[allan 295]

Throw a tank full of 98 at it and if anything like my old 530 will give you even more.

[euroriffic 603]

In my old e30 I didn't really notice much difference performance wise but economy was a good improvement. On a trip to Chch got about an extra 80km out of a tank

[_Matt_ 42]

My e28 burns 95 and 98 at about the same rate around town but on the open road 98 gives me a huge amount more mileage.

Edited April 6, 2013 by _Matt_