Griffith octane rating?

[griff59]

In the owners handbook it says not to use anything but 98 Ron, all of my local stations only sell Super at 97 Ron, I'm getting a little bit of popping on the over run in all gears, not sure if this is normal or if it's down to using 97?

[griff59]

Thanks, I'll try and find a Shell garage and see what happens.

[griff59]

Thanks folks, I'm not getting any pinking at all, it's just a little bit of back-firing on the over run.
There's quite a bit of unburnt fuel/oil...? on the garage floor below the exhaust outlets when I start the car, but I guess that's normal?

[griff59]

cavebloke said:

My pre-cat pops and bangs on the over-run no matter what octane is in the car. Sometimes (like north of Ullapool) I could only find 95 and the car (or perhaps the ignorant driver) doesn’t seem to notice.
Are you sure it’s fuel/oil under the exhaust outlets? That’s not normal but spitting condensation (ie water) which can be sooty and a tiny bit oily out the back is normal for mine on starting. I think it’s caused by hot exhaust gases hitting the cold exhaust piping when you first start the car but others might correct.
Cheers,

Simon

On reflection, I think you're right, sooty water it may be, looks like it, now you mention it.

[griff59]

I had a word about this whole octane thing at my club meeting, everyone said that they definitely noticed that using lower octane "regular" fuel gave a lacklustre performance compared to 97/98. It wasn't psychological, it was noticeable as a sort of "flatness" to things.

[griff59]

Pete Mac said:

I'm probably repeating what has already been said but the popping and banging is one of the 'charms' of a Griff, most do it. Popping and banging is very different from 'pinking'.

The blast of dirty water on start-up, mine does it as well.

I think its all down to a fairly old Buick engine being tuned to a level it was never designed for but having said that cars like the th F Type seem to have this popping and banging actually designed in.

I do run mine on the higher octane fuel but not too bothered whether it is 97 or 98.

Hope this give you reassurance.

Pete

I agree, it is a bit of a charm, I'm not getting "any" pinking at all. I'm just going to stick to BP97 from my local...I mean garage...not pub...