Fuel Additives

[scubasteve]

I have seen numerous ads extolling fuel additives, but, being advertisements, must be taken with a grain of salt.

I have heard that most of our type engines were made before the use of lead-free gas they tend to lose compression, and the wide spread use of added alcohol in gas makes the problem even worse.

They all talk about cleaning carb ports, fuel lines & etc.

How effective are they? Seeing as I would be putting them in a 40+ year old car, would they help? Are any brands better than others?

My TDr has been having starting issues, three or four cranks before it fires,vapor lock and rough idling while cold. My mechanic wants me to bring it back in to have him look at it again.

I drive it at least once a week, in May had a tune up; oil, points, plugs etc I should think there shouldn’t be these problems.

Thanks Again!

Amor Conquista Todo

[KentT]

IMO, you are smart to take those ads with a grain of salt. VW engines are essentially very crude by today’s standards, designed for simplicity and long-term reliability in adverse operating conditions, rather than performance or efficiency. Even by standards of their day – and the basic engine design dates to the mid-1930s, they were very simple (yet quirky, being air-cooled). They’re designed to operate in third world countries with low quality fuel, dusty/dirty roads, and owner-maintained with simple tools – that’s why they are low compression with a rudimentary fuel and ignition system. Yet, with solid mechanical valve lifters (rather than hydraulic, or overhead cam design), and no oil filter, they require frequent service compared to modern engines. If the car is being used regularly, you likely will see little benefit in using additives. However, today’s fuel with ethanol added is tough on old engines and fuel systems because it does not have the “shelf life” of 100% petroleum-based fuel and it tends to attract moisture from the humid air – both can lead to varnish buildup, and other issues if sits for extended periods. If you use it quickly (2-3 weeks) there’s typically no problems and no need for additional additives. Let it sit for months, and it causes a variety of problems. Ethanol fuit( has caused all kinds of headaches for both the Marine and Outdoor Power Equipment (OPE) industries because they are typically seasonal use and stored for long periods of time…

With all that said, there’s typically only two additives that I recommend. Stabil, if you are storing the engine or not using it (and replacing the fuel regularly with fresh fuel). And Seafoam if you are trying to clean the fuel system. If an engine has been sitting for months, I like to run Seafoam through it when I put it back in service, both initially and for the first 2-3 tanks of fuel. As long as I am using the engine regularly after that, and replacing the fuel before it can go stale, I don’t use additives.

 

My 2 cents, your mileage may vary…

 

 

 

 

 

Early FF TDr on 69 VW pan
Slowly coming back from the ashes...

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