Imperial Car Club Forum

I'm looking at a 1959 Imperial. The manual states it requires premium gas (leaded). With the problems we have with current gas, should I use the non-ethanol and mix any additives to the fuel? Thanks Doug

I think the key point is non-ethanol. Ethanol will attract moisture from the air, which allows moisture into your engine and components... rust and slush in your oil!

As for octane, I think it only matters based on your engine and the quality of gas in your area. If you hear it pinging when under load, such as going up a hill, then don't push it and try some higher octane fuel such as 93. If you can't get 93 but your engine likes it better, then as you say, your only alternative is to get some fuel additive to increase that octane.

Again, the largest destroyer of these classic vehicle engines is ethanol. Liquid corn in your engine is not a good thing. Even in modern cars, it reduces gas mileage, but modern engines handle the damaging aspects of it better as they use modern alloys.

Thanks for the info. Was wondering the same for my 74 (btw probably won't be delivered until the end of September, but that's actually worked out ok thanks to other logistical issues), and a few people on Facebook were quite adamant that I needed to add a lead supplement unless the engine (lifters, I think) has been upgraded to modern standards, which I very seriously doubt this one has

Too Many Mopars wrote: ↑Thu Sep 10, 2020 3:47 pm Thanks for the info. Was wondering the same for my 74 (btw probably won't be delivered until the end of September, but that's actually worked out ok thanks to other logistical issues), and a few people on Facebook were quite adamant that I needed to add a lead supplement unless the engine (lifters, I think) has been upgraded to modern standards, which I very seriously doubt this one has

I think it's more the valves and valve seats you want to upgrade. They need to be the hardened style to avoid damaging them. When there was lead in the gas, it would build up on those valves and act as a cushion to protect them.

It's also worth mentioning that wear on the engine components like lifters is due to the oil style we have today. The older oil had much more Zinc in it. So your best bet is with every oil change, put in a zinc additive to your oil. It's usually a small bottle you just pour in before you fill it with new oil. Similar to the lead in the gas, the zinc in the oil will coat and protect the engine components so the zinc is worn off instead of the steal.

That's right, the valves and valve seats.

Would it be a common thing to upgrade them? Unfortunately they don't know much about the history of this car but I'm guessing that it was just routine maintenance stuff.

And thanks for the zinc advice!

I've never replaced the valves. It's all in the head of the engine, so it shouldn't be too bad. From what I understand though, if you are going through the trouble of taking the head off, you might want to make a stop at a machine shop to let them even it out. From what I've heard, they could get some slight warping over the years and it doesn't take much to give your head gasket just enough space to blow out. You may need a machine shop anyway to press in the new valve seats... never done it, so don't have all the how-to details.

And don't forget a new head gasket while you're at it. Thoroughly clean off the old one any any other crusty stuff that might be on the metal.

I agree on the Non Ethanol gas, Octane Booster if needed. I use Marvel mystery oil in the gas too (4 Oz. per 10 Gallons of gas)