I quit the 3000 mi. change routine years ago, these days I use Mobil 1 Full synthetic. I change oil every 5000 mi. , BUT I change the filter @ every 2500 mi. I may be throwing money away, but I have peace of mind .... I also use 1 qt. of Lucas OIL additive when I change the oil, I also use the Lucas fuel treatment about every 3rd fill-up. I have never had to have my injectors cleaned yet , in fact I picked up about 3 mi. per gallon since about after 3 months of using it. I check my mileage @ EVERY fill-up, in a log-book I keep. I save my old oil to use for bar-oil in my chainsaws, and although it leaves a slight residue on the chain, it works fine. ....Boobala .....:smile: