I recently ordered 3 bottles of Auto-Rx (2 for the engine and 1 for the tranny) to put through a 1997 Subaru Legacy with a 2.2L engine and 170K miles.
Following along in another post, I see that some people recommend starting the cleaning process more gently by using a 15w40 diesel oil, and then using the Auto-Rx. This sounds reasonable to me.
My question is, at what point in the season should I use the 15W-40? I'm located in NE Pennsylvania, and the last date of freezing temperatures (32F) is usually the first or second week in May. Should I wait until it warms up a little before using this oil, or can I get the process started ASAP?
Following along in another post, I see that some people recommend starting the cleaning process more gently by using a 15w40 diesel oil, and then using the Auto-Rx. This sounds reasonable to me.
My question is, at what point in the season should I use the 15W-40? I'm located in NE Pennsylvania, and the last date of freezing temperatures (32F) is usually the first or second week in May. Should I wait until it warms up a little before using this oil, or can I get the process started ASAP?