View Full Version : leaded fuel

03-31-05, 11:15 AM
any of u guys with the older caddies running a lead substitute in the gas? would it be needed for a 1962 since it was before the switch to the unleaded gas. i heard it helps the older motors due to not being built like the newer ones. i dont want to kill my motor runnin bad fuel in it.

mario-62 sedan deville

03-31-05, 11:51 AM
Yeah, leaded fuel keeps engines clean on the inside, makes 'em run smoother. I think it also helps boost the octane but I'm not sure about that. The lead addative (or "leadative" as some people call it) is pretty cheap and it seems to work. I ran it in my 85 Pontiac once I cut the cat off. I'd say use it.


03-31-05, 04:41 PM
Older cars, typically 71 and older didn't have hardened valve seats, so they will tend to sink into the head with age and no lead. The lead acted as a cushion. As I have heard for years, "unless you do a lot of higher rpm driving, it is said that it really isn't an issue".

My 70 Pontiac 455 when I tore it down was fine. And it did not have hardened seats.

I wouldn't worry much, it will not destroy your engine, worst case at 150 to 200K miles when you are ready for a rebuild, you just have the shop replace the seats with hardended ones.

Lead was a great octane booster, one of the other reasons gas prices are higher now too. They have to use more oil to raise the octane. :(