TR6 TR6 Octane Outcomes?

[ichthos]

Hello All,
I need some information on gasoline basics. First, what are the effects of using different octane levels of gasoline for the TR6? What octane gasoline was originally recommended for the TR6? Does octane rating make a noticeable effect on engine performance? If I tuned my car using a gas with an octane rating of 87, would I have to retune it if I use a higher octane rated gasoline such as 89 or 91? An answere to any of these questions would greatly be appreciated.
Kevin

 

[Brosky]

I have used 93 octane, or as close as I could get to it for the past twenty years and my car runs great.

 

[Aldwyn]

I have the owners manual for a 74 TR6 here, and it says the engine was built to use a minimum of 91 octane.

 

[crj7driver]

I know the methodology for determing octane has changed quite a bit since our Tr's were made, so I am not sure how applicable the recommended 91 octane is to todays ratings. With that said you will get more power out of the lower octane gas as long as you don't get detonation.

These engine (in the U.S.) had compression ratios of 8.5 to 7.5:1 over the years. This hardly reguires the high test.

My motorcycle, for example, is 999cc and puts out 130HP at the rear wheel is 10.8:1 and definetly requires the highest octane possible, but it is much more high strung than the old tractor motor.

I run low to mid grade in mine and it runs great. I also live at high altitude and the motor has a lot less oxygen to play with.