AMGBA website home page or AMGBA Photo Gallery or AMGBA Club Blog

Join or renew for 3 years and receive a free t-shirt
or tech sections on USB flash drive /emailed/CD or past Octagon issues on USB flash drive/emailed/CD
see details in the join the club section at!

Gas Type

Started by 2022, August 09, 2022, 12:06:07 PM

Previous topic - Next topic

0 Members and 1 Guest are viewing this topic.


I have a high compression engine. in my B roadster. It seems my engine is a high compression engine and, in reading the owners manual, it mentions at least 98 octane and wants 100 octane. 

For those of you with a high compression engine, are you doing this or is premium okay?  Are you adding an octane booster?

Stephen Naylor


I never saw a "B" manual that said 98 or 100 octane gas needed. Neither is commonly available at pumps in the US (or the UK). 89 is the best choice at the relatively low compression these so called "high compression" engines  have, but 91 won't hurt.

Some, but not many stations have 93 octane instead of 91. This usually not needed unless the compression has been modified .

Mark Huff
American MGB Association
phone/text: 773-769-7084

North America's oldest and largest club for all MGBs, MGB-GTs & Midgets.  A nonprofit organization founded in 1975 and offers color magazines, emagazines, technical advice, member recommendations on service shops, registration of your MG, a tradition of service & FREE member classified ads that appear in the magazine & on the website.

   back to AMGBA website home page or AMGBA Photo Gallery or AMGBA Club Blog