I know that the MGB owner's manual specifies high octane gas, over 94 I
think. I've been running the 93 but wonder if this is overkill. Does
anyone know if 89 octane is
sufficient, or should I try it and see? BTW, I'm curently getting about
17-18 mpg on a newly rebuilt engine. What can I expect after breakin??
Ira "There are no stupid questions, only stupid answers" Weiner
Marlboro, Vermont
'68 'B'
Ira -
' Don't know what year & carb set-up you have. My '76, rebuilt 20,000
miles ago has the earlier 8.7:1 pistons, a Schneider cam and HS-4s. Like
you, I've run 93 octane most of the time, but have tried an occasional tank
of 89 - and it seems to ping a bit more with it. I'm inclined to stay with
93. Mileage is never less than 26, and with overdrive, when I get out of
the mountains and cruise on those midwestern interstates, 30-34 mpg is the
norm. I'd say your 17-18 is a little on the low side - I don't recall
figures that low during break-in. (Although I remember looking at EPA
ratings on new Bs in the late 70s claiming 18 mpg!) My 73 B and BGT don't
get quite that kind of mileage but both will approach 30 mpg on level
interstates, and bottom out around 22-23 mpg in commuting. The GT engine
is now rebuilt but still out of the car. It has +.030 8.7:1 pistons, BL1
cam and the stock HIFs - I'm anxious to see how it works out.
Regards,
Allen Bachelder
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