Tarry and I are in OKC and found out about a free 20-point Cummins engine and also Onan genset check being offered by Cummins Southern Plains.? They have 7 dealerships, 2 in OK and the others in TX.? I took advantage of it and they found a leak in the CAC system which probably has been affecting my fuel mileage.? Their web site is http://www.cummins-sp.com/.? The offer I believe is through June 15.? The check was very thorough and in my case productive.?