Re: Which fuel is recommended?

Posted by Owen_Dyneto On 2008/7/23 19:02:07

Two comments. Here is NJ is just paid $3.81 for regular (non-branded) gas yesterday, down from a high of about $4.05 a few weeks ago. Seems a bargain!

Concerning tetraethyl lead and octane, I pretty much agree with the prior comments of Rusty who is always right on target. Before I had my 34 Eight rebuilt (has hardened exhaust seats now), I bought regular gas (87 octane, and certainly didn't even need that) and added genuine tetraethyl lead every other fillup, not to increase octane (CR is only about 5.5/1) but for valve stem and seat protection. Whether I really needed it probably depended primarily a bit on driving conditions. If I were to drive the car at 55 mph or so (the practical limit, esp. with the 4.69 rear) for sustained periods the lead was probably useful. For just local driving I probably could have gotten along fine for tens of thousands of miles without it.

My 56 Caribbean gives quite a bit of ping even on modest acceleration with 91 octane, and even Sunoco 93, and knocking back the timing a few degrees so degrades the performance I decided to add tetraethyl lead to boost the octane, and continue to do so. Perhaps the heads were milled once, don't know. I keep looking for a set of the export head gaskets which reduced compression for the generally lower grades of gasoline then available overseas.