Mixing fuels

[JetspeedCamry]

If I were to mix half a tank of normal unleaded fuel and half a tank of premium unleaded, what is the net result?

Normal fuel = 91RON
Premium fuel = 98RON

Would we get 94-95RON?

[Wibbit]

i dunno if youd notice any difference regardless. Holden specifies about 2kW increase on an SV6 if you use premium as opposed to regular unleaded... big deal. not really worth filling Optimax unless youve tuned for it

[JetspeedCamry]

Nah nah mate..just want to know what OCTANE you'd get if you fill half premium, half normal.
Lets say you fill your tank with 98RON fuel, then the fuel gettn to your engine is gna be 98RON. However, if i had half a tank of 91RON unleaded fuel, and fill the rest with 98RON Premium, what is the result? What ocatane?
The reason I ask is because I'm trying my timing on 16 degrees and ive still got half a tank of normal fuel left, and it's pinging! So was wondering if i should just burn the rest of the tank off or fill it up with optimax (premium).

[Wibbit]

lol ok no idea...

but if its pinging then i reckon waste the regular and fill up with optimax!

[crah]

You would get the the average of both fuels. That's what they do for the middle grade. They just mix the high octane and the low octane. So in your case if you mix it exactly in half you octane would be 94.5.

I hope that helps.

[JetspeedCamry]

Great, thankyou for your replies.
I think i might aswell just burn off the regular fuel and fill it right up, which means ill have to drive tamely until that time!

[1C8 Streak]

Just don't ever add half a tank of deisel fuel

[JetspeedCamry]

Hahaha. No.