Loudnproudford

Thanks franchi!

Loudnproudford

Okay I just fiilled up with 19.6 gallons on 93 with about 1.4 to 2.0 gallons of 87 still in there, would I be okay running on the canned 93 tune?

Loudnproudford

Anyone?

charliedyal

You will be OK. You could always add some octane booster for peace of mind.

Tackle

If there is even the slightest bit of worry, drain it down again then fill up with 93 again.

MGD

Hi.

Using an overabundance of caution. I'd run the 91 octane tune until you next fill up with 93. Yer 93 is now diluted - best-case yer PCM will detect knock and pull timing which will hurt performance.

BTW - NEVER use an octane booster! The stuff is crap and can hurt O2's and cats. And the quantity you'd need to actually make a difference is much greater than you think - when they say octane 'points' they mean fraction of a full octane number ( e/g 0.1 point versus 1.0 point ).

I also concur - don't touch timing unless you know exactly what yer doing - you have access to both Global and RPM-specific spark adders, but you don't know how much to add/remove SAFELY. The knock sensing systems in these trucks is so good that simply going by what knock you can hear is purty much futile.

Good luck
MGD

Loudnproudford

Thank y'all for y'all's help!