> The gas stations I use always seem to have "premium diesel" but
> not "regular diesel."  (I'm not diesel)

Dan:

The premium diesel usually has a higher cetane rating than the usual 41 rating of standard No. 2. This fuel is a bit closer to kerosene and with the lowered sulfur levels mandated by Algore and his associates, lubricity of the Stanadyne injection pump may be of concern. Stanadyne makes two diesel additives that should lengthen the life of these pumps whether one uses regular or super.

Premium diesel is used effectively if you are doing a lot of city driving with long idle periods in between similar to a delivery truck. The particulate stuff is just a little bit less after combustion.

As I said earlier, there are two formulations of the Stanadyne additive. The first type is mainly a concentrated lubricant and not much else. This was mainly used in air ports for the service vehicles that had diesels burning Jet A fuel. While No. 2 diesel storage is done, it is much safer for these authorities to store Jet A in their buried tanks so there will not be any incredible screw up's. This fuel has almost no lubrication as far as diesel requirements are concerned. This additive is also used in blown monster diesel pulls at shows around the country.

The second Stanadyne additive has a bit less lubrication enhancement but other goodies are added. A cetane boost along with detergents and lowered wax temperature enhancements are a bonus for our service. The lubricity offered in this formula is more than adequate even for the old 6.2 liter DB 2 Stanadyne pumps with the chrome rollers. The optical sensors in the newer pumps are supposed to be kept cleaner with the detergents used in the second formulation. When this sensor can't see, the pump has to be removed and what a pain on these engines, especially on our trucks.

Since I began using the second formula, the violent crash rattle on startup has decreased dramatically and the warm idle now has only the faintest diesel rattle. At first, I thought it was the old washed truck seems to run better syndrome. Since my wife has a 98' I noticed that her (If you will pardon me) cold start crash rattle (In her hummer that is) was much louder than my 96' with a new 97' long block. (Long story) We are now using the additive in her truck.

Look in the yellow pages under diesel and find your local Stanadyne service representative. Drive over and chat with them. You will find a wealth of information on these pumps and most of them will work with you directly after YOU remove your defective pump. (In the future) Their exchange prices are usually far below the typical GM dealer after his labor tack on and resale. Granted, you will be paying an inflated wholesale, we are capitalists, right? Some Stanadyne reps. will remove your pump and if ya ain't comfortable about doin it DONT.

John W. Watkins Jr.