Feeding a Bug

[rokemester]

Can unleaded fuel be used safely with a VW beetle? Back in the 60s leaded and unleaded fuel was available. The leaded fuel provided additional lubricity agents which protected the engine. Modern engines don't require the lead additive.

What motor oil is safe for these older engines? I remember using monogrades when I owned my VWs back in the 70s. Again today's motor oils are specially formulated to meet the needs of modern engine designs.

[couion]

The lead was added to gasoline to lubricate the valve seats. If your car is still running the original heads it probably has lead imbedded into the seats and will be fine on unleaded gas. If it is running newer heads then the seats were likely replaced to the hardened seats for unleaded fuel. If you are having issues with the engine rattling I would try a lead substitute. If not I wouldn't worry. The oil question can be answered like this. I personally run a quality 10W 40 or a straight 40 oil. Todays lubricants are way more advanced than they used to be as long as you change it regularly you should be fine.

[Blue Baron]

Recent federal regulations for motor oil has mandated the severe reduction of zinc in passenger car applications. This is important because zinc is an anti-wear additive, and without a sufficient amount of zinc in the oil, there is nothing to cushion a flat tappet as it moves against the cam lobe on our pushrod engines. In modern cars with a timing belt and overhead cam, the reduction of zinc is not as critical.

The reason for the reduction of zinc is because it's been found to damage the catalytic converter, and is also being reduced for emissions purposes.

The higher level zinc containing oils are designated by the American Petroleum Institute (API) code "SL" or earlier. Any oil labeled by the API as "SM" or later does not contain enough zinc to protect the cam and followers, and you can expect serious wear on the tappets and cam. Only oils blended to SL standards or earlier contain enough levels of zinc needed to protect the valve train.

The API service symbol is a donut on every quart of oil. It will list whether it is an SL or SM oil. A good substitute for passenger car oil is oil blended for diesel engines. (The fact that it's diesel makes no difference.) All diesel formulas are SL. Also, oil formulated for motorcycles also contains the higher zinc levels, but tends to be more expensive. There are also additives, such as STP 4-Cylinder Oil Treatment (red bottle) that will add protection to modern oils.

Remember SL means Life!
SM means murder for your engine!

[rokemester]

What about using a fully formulated synthetic like Mobil 1? I appreciate your very thoughtful post about oil quality and description of various oil formulation components. The OEMs and major oil companies are working diligently to minimize the use of zinc in modern engine oils.

My bug has been sitting for 4-5 years. You are supposed to drain the engine oil when the engines is warm, but I haven't gotten around to starting the engine, I'm focused on stopping Murray first! Should I drain the oil cold, and top off with a quality engine oil? Once I get it started, run the engine until warm then drain the mixed concoction, clean the screen and refill?

[Blue Baron]

The Volkswagen engine is not only air-cooled, it's oil cooled, and I've read reports that state that synthetic oil doesn't have the same heat dissipation capacity as standard oil. So you must ask yourself, do you want to experiment with your engine?

Plus synthetic oil is more expensive, so for me it's a no-brainer. Use regular oil with an API service rating of SL or lower. (SK or SJ is even better.)

As for the brand, I think it's more important to change the oil often than what brand oil you use. (2,500 miles is not too often.) And so did the factory, which is why Volkswagen never recommended any specific brand. I like using 10W-40, but switch to 20W-50 in the hot weather. (I'm in Florida.)

As to changing the oil with the engine warm, I don't think it makes a huge amount of difference. Just be sure to clean the filter screen and oil sump plate and install a new pair of gaskets. Also, if your bug has been sitting for four years, you should adjust the valves while you're under there.

[rokemester]

Thanks Blue Baron, great thoughts. I've been focusing on stopping Murray, but last night before turning in I drained the oil. There was some sludge which I imagine came from some condensation contaminating the oil over the years sitting. I like the idea of using a HD oil vs. PC, and completely agree that frequency of the change is most important.

I was thinking how optimistic I'm being regarding starting this little beast. If the brakes are any indication I'm going to be spending a significant amount of time just getting this little guy to fire!

[Blue Baron]

You shouldn't be. I've had no problem getting a car to fire that's been sitting for years. Along with the oil change and valve adjustment, you should pull off a coil wire and crank the engine for oil pressure before actually attempting to run it. All, be sure to replace all that rotting old gas line with fresh German gas hose.

[bsflyboy]

Excellent article on synthetic oil in air cooled engines.

http://www.aircooled.net/gnrlsite/resou ... nthoil.htm

We use it exclusively in the airplane and it runs about 25 degrees cooler!