Primrose 405 and 409 usage questions

[dschultz]

I decided to use the Primrose 405 and 409 products in my DMAX after reading the fuel quality threads.

Globs of rust goo in the water sensor helped me decide too. :mad:

What quantities of 405 (summer) and 409 (winter) should I be using? I started out with 3.5 ounces of the 405 in my 56 gal Transferflow tank.
I based this on the 12 ounces to 187 gal ratio and assumed no more than 50-53 gal in a complete fillup.

Should I use the 409 alone in the winter? Or should the 405 be used with the 409? I live in Norther Virginia and it usually doesn't below 15F around here.


On a related note:

I have a dose of 405 in the truck now and it seems to run better; smoother, better throttle response. Is this just in my head or is this thig running better?

[george morrison]

Primrose 409 is 405 with pour point reduction. So, simply, Primrose 405 all summer, then switch to 409 come winter.. All of the good properties of 405 (lubricity enhancement, corrosion protection, cetane boost, water emulsion) plus cold weather protection..

One does not need to 'overtreat', although it certainly does not hurt anything using higher treat rates. Some 'feel the difference' with higher treat rates and prefer doing so..
And cetane does continue to increase with higher treat, but rate of increase of cetane reduces, depending on the fuel being treated.

The optimum treat rate of one ounce Primrose 405 to 15 gallons diesel and one ounce of Primrose 409 to 8 gallons of diesel yields the best cost/benefit ratio. Again, increasing treat rate yields benefits but cost/ratio decreases.. If used at optimum rate, the increase in fuel mileage more than offsets the cost of the Primrose 405.. If performance alone is the goal, then increasing the treat rate will provide increased performance but the cost payback will be reduced.
George Morrison