how many miles with valvoline 10/30 VR-1
 

How many miles do you guys run Valvoline 10/30 VR-1 oil?

VRI or Pengrade--3000 miles or two years, whichever comes first.

Max of 3k or once a year

If you want to know when to change oil there is no better way to get optimize mileage and time than oil analysis. The condition of the engine and driving habits as well as where you live all figure in to the formula. Send a sample off and find out if you're able to extend oil changes, or if you should be doing it more frequently. oil analysis also will reflect on the actual condition of the engine as well as the tune up. Let you know if head gaskets are seeping, and coolant is getting into the oil. You may be changing oil prematurely, or you may need to change it sooner than you currently are. Oil analysis will let you know for certain which way you need to proceed

https://www.blackstone-labs.com/

If you want to safely extend oil changes you need to step up oil filtration to a much higher level through an auxiliary by pass oil filter. There is no downside to having clean oil that is filtered to a much higher standard than any OEM filter will clean it. Running extra filtration, and using oil analysis will let you change oil at optimum times. Without some knowledge about your oil condition, you're just guessing, along with everyone else.

https://www.frantzfilters.com/

It's your car, and your decision.

I'm running a modern, high-zinc fully synthetic oil in my '65. I'm just curious as to everyone's thoughts on this:

I put less than 1000 miles a year on my car. It's strictly a fair-weather cruiser and is not raced or abused. The car is stored in a climate-controlled garage. Can I safely extend my oil change intervals to 2 years? I guess what I'm really asking is this - does synthetic oil "break down" over time like conventional oils do? Aside from getting dirty (which mine doesn't appear to be), is 2 year old synthetic oil still performing as designed?

https://www.youtube.com/watch?v=W48nygk1mlc
Watch this.

I have a fleet of old cars, have been using diesel spec oil in them all for the past 23 years, and change the oil at 3000 mile intervals. That usually takes two years, but on a couple cars, it can take 4 or more. I've never had an issue, and have done teardowns and reseals, and the engines and bearings look excellent. Currently have 90,000 miles on the rebuild I did on my '67 37 years ago, and when I resealed it in 2011, it still looked new inside (80+k miles at that time). Disclaimer: I don't over-rev or race my old cars. Diesel spec oil is not intended for high RPM use due to anti-foam qualities.