I have four cars that get low usage and like some input on the OCI. Right now the OCI is 6 months, but I like to extend this to once a year if possible. I contacted Blackstone Labs and they said it would be difficult to get a good analysis on the 200 mile OCI unless there is a major problem. Condensation and acids are a couple of concerns. Temp cycles are full four seasons ranging from 20 - 95 F, all engines in good condition, all use 10w30 conventional mineral oil , all stored outdoors except the Toyota.
1983 Pontiac 6000 STE 500 miles year, 30 minute trips
1987 Nissan Maxima 1000 miles year, 10 mins trips
1994 Dodge Stealth 100-200 miles year, 30 minute trips
1999 toyota, Avalon 1000 miles year, sludge prone eng, plan to keep 6 month/500 mile OCI. 10 minute trips, 2 hr trips 4 times year.
1983 Pontiac 6000 STE 500 miles year, 30 minute trips
1987 Nissan Maxima 1000 miles year, 10 mins trips
1994 Dodge Stealth 100-200 miles year, 30 minute trips
1999 toyota, Avalon 1000 miles year, sludge prone eng, plan to keep 6 month/500 mile OCI. 10 minute trips, 2 hr trips 4 times year.