Ok here is my formula, 6 gallon used veggie oil, 2 qts k-1, 1qt reg gas, 2 ounces naptha paint thinner, 4 ounces Power Service. Run it all weather, seen ice freeze on my 70 micron auxilary filter under the cab and no gel problems. Reg gas is a biocide so no black death from bugs in the tank. Every oil change put in a full tank of diesel with two bottles of Stanadyne and do a Italian tuneup. Put her on the interstate and run her uphill at 75mph in third gear then cool her out in overdrive. Head of Mercedes classic car mechanical troubleshooter reccommended Italian Tuneup, his name is Tom and unlike the rest of the world he is happy to discuss their diesel engines and alternative fuels. My old girl has 326000 miles and the last 20000 were running raw veggie oil. She runs like a scared haint!!!