Penray Products -- additives & chemicals

Capt. Mike

I'm not going into a full post about Penray's many products. They have a web site, for more information or you can request catalogs through them or Cummins. They are the official supplier to Cummins Engines.

For an idea of some of their products, see the Lubro-Molly post. Penray makes equivelants of most of those products.

A product I have switched to is their MAX POW-R PLUS Cold Weather Diesel Fuel Treatment. This effectively replaces the LM Cetane improver and anti-gels in one can. It also adds lubriciity, FI cleaners and water dispersants. Since a can treats 125 gallons instead of LM's 25 gallons, and the price is about half to boot, you can see it's attraction in my diesel vehicles.

Diesels also call for an anti-fungi & bacteria product. I know, sounds crazy, but diesel can actually support and become contaminated with bacteria and fungi that will clog up the system. An old and excellent product for that was called Diesel Doctor, which came in a tube and a tube full would treat a typical auto tank. It was dropped once, but I see recent ads indicating in may be back in production. Again, a product I put in the tank before a fuel filter change.

However Penray makes another, Fuel-Prep 1000. It has an amazing side effect, it becomes a fuel preservative.

Fuel-Prep 1000 is again concentrated for the big rigs so a pint treats 125 gallons. Even the big tank on my Cummins Dodge truck gets just a few ounces. But the good news is that the anti-bacteria agents don't hurt gasoline, so it can be used in gas cars as a fuel preservative or stabilizer. Penray suggests a double-size dose when used as a gas storage stabilizer. Works great in my generators, chain-saws, antique cars, and perhaps your Westy if it isn't driven regularly. An excellent replacement for the grossly overpriced Stabil at the hardware store!

Caution: Penray supplies the big truck market; even gas engine products are still geared to that end. So you will often find their quantities and concentrations more suited to that market than home use. Also, they provide many specialty chemicals for big rigs & diesels which ARE NOT suitable for automotive use. So don't just rush in and buy something because it's cheaper -- be sure it's intended for YOUR use in your aluminum VW engine! And then measure quantites per directions.

Capt. Mike

I recently made a trip into northern Wisconsin in my diesel pickemup truck. Everything went fine until we hit -21°F! Big truck started fine -- it was on a block heater -- but a couple of days later when I went to fill the tank and the temperatures had warmed up to several degrees above 0°, my Penray anti-gel was frozen solid! That's a kick -- you're anti-freeze is frozen.

I've contacted Penray and they quickly responded that they have discontinued the combination product Max-PowR-Plus. The replacement anti-gel, Winter PowR-Plus is supposed to have a better flow point. It also contains the cleaners and stabilizers of the previous product.

In a side note they point out that cetane improvers are most likely to be Madison Ave. hype as the amount of additive necessary to improve cetane would exceed the bulk volume acceptable as an additive. When the additive starts to be measured in "gallons", I guess it quits becoming an additive.

Another note was the "lubricity" scare of years ago. In a separate posting on their internet site, they point out the original fears of failure due to lack of lubricity with the new low-sulfer fuels turned out to be a seal failure when the seals had been attacked and hardened by the high-sulfer fuel and were now deteriorating as the low-sulfer fuel cleared them out. Thus "lubricity" additives are being phased out of the additive packages.

Will try it next year since winter is about over and anti-gel isn't a big need in the South anyway.
Last edited:

Capt. Mike

Penray has expanded their automotive and retail product line. Super-X and JetGo are two product lines you may find in the more conventional retail outlets and auto parts stores. They usually replicate the heavy-duty truck market products but in concentrations designed for auto and small truck use. For example, Super-X #320 and JetGo #J260 Diesel fuel conditioner with anti-gel both use a 12 oz. bottle for a 20 gal. tank. Winter Powr-R Plus #202012 uses 12 oz. for 125 gallon saddle tanks.

There may well be other changes so I can't vouch for 100% interchangeability. However, Penray is a respected name and I would assume their Super-X and JetGo lines to be satisfactory if used in accordance with label directions. They also make private-label (store brand) products but those products are at the mercy of the label and I can't recommend them as suitable replacements for the original Penray products.