Regular or "Ethyl" ??

James Fischer

James Fischer

PCS Member
So since I cant afford to convert the 72 Caddy to all electric (rememberI am in Calif) or even hydrogen...I will have to keep buying fossil fuel for now........
What is the consensus for what grade fuel to put in her ? Regular with a lead additive or premium ??
Suggestions would be appreciated.......
 
I run regular in all my engines, except for the 2 cycles... They get the expensive gas without Ethyl.. Can't justify the extra cost for the higher octane fuel, since it doesn't improve mileage enough to warrant it. Might push the overall MPG up 1/2 to 1 MPG more at best. I don't use a lead additive in the engines either. The current thinking is that most these engines already have hardened valves and seats, and there is no need for the lead in them. Also, the residual lead in the combustion chamber is usually enough to get by with.
Oil on the other hand, it is important to add the ZDDP to all modern engine oils.
 
Your 1972 is the first year that unleaded fuel is recommended. If you are concerned just add a little transmissionn fluid to the gas to lube the valves and I usually run super-unleaded for the octane 91-93. I get about the same fuel ecomomy in my 64 using the super in town, but on the interstate I can get 22-23 mpg. The cheap stuff here is 87 octane and my valves clatter and I have to readjust the timing so it doesn't sound like a thrashing machine.
 
the gas up here in Ontario is CRAP ! the new fuel lasts maybe if your lucky 15 days then its starts to go stale....what I do is run high octane in my 2 stroke small engines and run reg unleaded with "stay fresh " added in the gas. In my 87 Eureka I only leave enough gas in it ( with the stay Fresh" ) in the tank to get me to the gas station next time I take it out for a run...then she has fresh gas in her.
 
my advice it try it and see. only you will know what works in your location for you. at 3434 ft in elevation we need the higher octane in the higher compression engines they run a lot cooler and smother but you may not. I'm with the only keep enough to get to the station in the car also group. but i find that the etoh blends here will keep better.
 
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