I'm a change the oil often guy. Usually at the start of the summer season on my cruisers (depending on miles driven) and every 3000 on my beater. I bought all the 10-40 and 10-30 wt, 5 gallon jugs of Master Mechanic when my local True Value closed for $9.00 each. I also picked up Purolator Filters on close out at Rock Auto for $2.00 each. So now I have enough to do 15 $11.00 oil changes. I will probably use Valvoline or Napa oil on the first oil change on the new Diplomat until I see if it uses oil or not.
If I build a new motor it will get the good stuff, probably Valvoline Racing. But until then I'm cheap and can't see spending the money on higher mileage cars.