Re: Unleaded

Posted by Craig the Clipper Man On 2016/6/27 14:45:04

This is something I just found on the Kelley Blue Book site regarding octane levels of gasoline:

"Does an Occasional Tank of Premium Help Keep a Car's Motor Clean?

As strange as this question sounds, this is a common and long-standing practice among many motorists who consider an occasional tank of premium a special treatment that will help their engines last longer.

The basis for this assumption is that a tank of higher octane gasoline, maybe because it costs more, will somehow reduce engine wear. The assumption is fundamentally incorrect, though an occasional tank of premium may help an engine in other ways.

An engine's design, which includes such factors as its combustion ratio and its operating temperature, is related to something called an octane rating. Usually, we think of an octane rating as something that applies only to gasoline, but the engine itself has such a rating that represents the minimum octane level that the engine requires for proper operation.

An engine needs a minimum level of octane to avoid ping, which is caused by uncontrolled combustion of fuel inside the cylinders. Excessive ping can severely damage the engine. The octane rating on the gasoline is a measure of its anti-knock or anti-ping properties.

If your car does not ping on regular, then there is no reason to seek a higher-octane gasoline. The anti-knock level of the regular in this case is adequate for the engine.

But as a car gets older, depending on how the car has been driven and cared for, it may need a higher-octane gasoline anytime between four and six years. That's because carbon deposits inside the cylinders raise the combustion ratio, which in turn raises the engine's octane rating. You may notice that your car operated fine on regular fuel when it was new, but pings on regular as it gets older. So, the higher-octane fuel is not something to pamper a new car with but rather help keep an older car running properly.

In addition, premium gasoline has some other selling points. Most premium gasolines have a higher-quality additive package put in at the refinery. The actual additives in a particular brand of gasoline are generally not disclosed by refiners. But usually they include detergents and other solvents that keep the carburetor and rest of the fuel system clean."

This article, of course, relates to cars probably no older than 20 years, whereas the "newest" Packards were built about 60 years ago (apologies to Studebaker). But I think the message is still relevant. Back in April while on a tour in Virginia, I filled my '55 Clipper with regular unleaded gas that did not contain ethanol. I did experience some pinging and the performance was sluggish. Other members with older, lower-compression engines did not have that problem. When I refilled with premium, my car definitely ran better.

Bottom line: If your car runs fine on regular gasoline, then that is what you might as well use. If nothing else, it will cost you less to fill up, thus saving you money that is better spent on beer or wine!