Classic Car Gas and Oils

Q.

I just purchased a 1957 Ford Skyliner and have questions about correct gas and oil uses. It is un-restored and looks like it just rolled off the assembly line in Kansas City where it was built minus the 60 year old normal where and tear because it was not in a museum. My question is about gas and oil. It has the 312C.I. Thunderbird Special engine. The seller bought it and a 1968 Chrysler 300 from his mechanics neighbor, whose husband passed away. He said he has been using unleaded gas for the short time he has owned it. Is that recommended or is there an additive to be used? Also what kind of oil should be used for it?

A.

Gas and oil are certainly two topics that can start a lively conversation amongst car enthusiasts. Let’s take a look at gasoline first.

Tetraethyl lead was originally added to gasoline to cheaply boost the octane levels as opposed to further refining although in high-performance applications it also served as a buffer against micro-welds forming between the hot exhaust valves and their valve seats. Without the lead these micro-welds occur when the valves are closed, when these valves reopen the micro-welds pull apart and leave the valves with a rough surface that abrade the valve seats, leading to valve recession. When lead was phased out of motor fuel, the automotive industry began specifying hardened valve seats and upgraded exhaust valve materials to prevent valve recession without lead. If you drive a vehicle conservatively that doesn’t have hardened seats and valves you will likely not have any problems, however if you sometimes use your car for performance driving (drag strip, road course etc…) you should consider gasoline additives or having stainless exhaust valves and even hardened seats installed in your heads. There are a number of lead substitute additives on the market, and while I don’t believe they’re necessary for non-performance driving, they do give many classic car enthusiasts a degree of “peace of mind”.

Perhaps a bigger concern with modern fuels and classic cars is ethanol. The alcohol in modern fuels does cause it to burn cleaner it can be detrimental to older fuel systems. Vintage carb seals, fuel pumps, o-rings, fuel lines, fuel filter and fuel level floats can all be damaged by ethanol. Most states allow distribution of non-oxygenated fuels for classic cars, ask around to locate a service station that carries it near you.

Most standard “off the shelf” oils at the local auto parts stores are not good choices for your classic car. Modern oils lack sufficient zinc (zinc dialkyldithiophosphate) to properly lubricate flat tappet cams and lifters, especially during startup. The zinc was removed from modern oils as it caused carbon to build up in the exhaust system causing catalytic converters to prematurely fail. You have a couple of options, either use oil specifically blended for use with classic cars that still contains zinc or adding a zinc additive to modern oils. Which one is best? That’s an argument I don’t want to get into but here are a few options to consider:

Oils: Lucas Hot Rod & Classic Car Oil, Valvoline VR1 Racing , Amsoil Z-Rod, Brad Penn ‘Penn-Grade 1’, Royal Purple HPS, Shell Rotella Diesel Oil

Additives: Cam-Shield, ZddPlus, Edelbrock High Performance Zinc Additive, Eastwood ZDDP

I am sure there are dozens I left off this short list, but I’ll post this reply on the site and am certain we’ll hear from fellow members their thoughts as well.

Wrench Safe,
Mark

Discussion
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15 Responses to “Classic Car Gas and Oils”
  1. DENNIS

    Was interesting to read about the lack of zinc in newer oils. I’ve been using the partial Synthetic oils in my older cars, 1964, 65, & 78. And of course alway premium gas, and without the ethenol. And then I add and additive like “Instead O lead”, to help with valve wear, etc. wish I could still get real leaded gas. I haven’t go it running yet, but I’ve heard that Royal Purple would be best for my 1937 Packard Six Touring Sedan. Is that good advice?

    Reply
    • Customer Service

      Hi Dennis. Royal Purple resisted the move to eliminate zinc in it’s motor oil for some time.
      Although, I believe their current standard oil has eliminated the zinc.
      They do offer Royal Purple HPS oil that still has high zinc levels, also they offer a high zinc break-in oil for new engines.
      Thanks
      Mark-CCRC

      Reply
  2. Wesley Edens

    Lucas oil for hot rods (listed). Is it an additive used as a small amt. to be used at each oil change or is it a 5 qt. addition?

    Reply
    • Customer Service

      Hi Wesley. The Lucas Hot Rod motor oil is a full “high-zinc” motor oil, that is formulated for older classic cars and hot rods using flat tappets (non-roller lifters).
      Lucas also offers zinc (ZDDP) oil additives also.
      Thanks
      Mark-CCRC

      Reply
  3. Drew

    If you have a friend at your local airport, you might be able to convince them of your need for leaded gas purchase “avgas” or 100LL Aviation gas. It is 100 octane low lead alcohol free gasoline. Price is high so be prepared.

    Reply
  4. Glenn Swaney

    Can I add the zink compounds to full synthetic lubricants? I am currently using Pennzoil full synthetic in my 57 Chevy.

    Reply
    • Customer Service

      Hi Glenn. Yes, There are several good zinc (ZDDP) oil additives on the market.
      They are a very good choice for flat tappet motors, and an absolute must when breaking in new flat tappet motors.
      Thanks
      Mark-CCRC

      Reply
  5. David Nepley

    Why not mention STP which contains ZDDP, the regular blue bottle and the harder to find red bottle, that contains extra ZDDP? STP can also be added to old manual steering boxes to slow leaks, even using straight STP in them, or any motor “honey”.

    Reply
  6. Ron Stanley

    Hi, Enjoyed this article and would like to add my two cents worth. I have owned older cars since I was a teenager which was more decades of life than most folk are fortunate enough to have. Most of my old rides were flat head Fords and Mercurys. All the guys that I hung out with used SAE 30 with a non detergent rating. I recently purchased a ’39 Ford with a ’53 flathead and the old reocuring thought of what oil to use again came to mind. At a recent Goodguys event, I stopped by the H&H Flathead booth and asked about the up to date thinking on oil use. The answer that I received was one of the oils mentioned in this article “we use Valvoline VR1 20-50 in all our rebuilds, it has a high zinc content”. My immediate thought was ” multigrade in an vintage engine?” Then, yeah why not. I guess it seemed strange because multi grade hadn’t been born in the 50’s. The next day I purchased a case and gave my old flattie a taste of something new which has also given me a little peace of mind. Happy Holidays to all you old car nuts !!!

    Reply
  7. Lou Helbling

    You left a few oils off your list which you should have perhaps mentioned. Chief among these is Kendall GT-1 competition motor oil. Some of the benefits include:Exclusive Liquid Titanium protection additive provides extra protection against engine wear
    Formulated for engines equipped with turbochargers or superchargers
    Excellent resistance to viscosity and thermal breakdown at high temperatures
    Protects against sludge and varnish formation
    Protects against rust and bearing corrosion
    Highly resistant to foaming
    High ZDDP content for additional wear protection for engines with flat-tappet camshafts (SAE 20W-50)
    Racetrack-proven performance
    taken from their website.

    Reply
  8. Roger

    I helped develop additive systems in the oil industry for over 40 years and my recommendation for classic car engine oil is using a HD diesel oil. HD diesel oils contain almost twice as much ZDDP ( zinc anti-wear) as do modern PCMO,S ( passenger car motor oils). I use a 5w-40 vis which will handle both low and high ambient temps.

    Reply
  9. Michael

    I’ve been adding a lead substitute & Mystery Oil to my 10W40 motor oil in my Chevy 283 engine with no noticeable problems over the last 20 yrs. Is this good, or bad? Is the HD Diesel Oil, 5W/40 better? Choices, choices, choices. What’s the best for my baby?

    Reply
    • Customer Service

      If you’ve been running this combination for 20-years without problems I would hesitate to change anything.
      Diesel oils have begun to remove the zinc also, so don’t count on those anymore.
      Adding zinc is most important on newly built flat tappet engines, as the engine breaks in they become less important.
      personally a continue to use zinc additives in my flat tappet engines after break in, for added protection.

      I’ve never used Mystery Oil in my engines, however I know plenty of enthusiasts who swear by it.
      So if it works for you… keep using it!
      Wrench Safe, Mark

      Reply
  10. Mike the Oil Guy

    I’ve worked in the fuels and lubricants industry for 38 years and have formulated many types of oils for large and small lubricant companies. I agree with Mark’s comments. At all costs avoid any fuel with ethanol. You will pay a high cost if you do not. Also, I would recommend oils which contain 1000 – 1200 ppm zinc content. You will not find this amount in current API licensed oils. I would also recommend checking out Driven Racing Oil’s product line. They market oils and fuel additives suitable for classic and vintage cars.

    Reply