Which oil would you choose to leave in forever.
I put 40wt redline in the 75 vette several years ago and plan to leave it. I have $2 valvoline 5w20 in the old 84 suburban and Mobil 1 sale oil in the 02 suburban.
I plan to continue to change the 08 mustangs oil every couple of years. I have to change the trans AM's oil every 3-6 months due to coolant contamination.
I put 40wt redline in the 75 vette several years ago and plan to leave it. I have $2 valvoline 5w20 in the old 84 suburban and Mobil 1 sale oil in the 02 suburban.
I plan to continue to change the 08 mustangs oil every couple of years. I have to change the trans AM's oil every 3-6 months due to coolant contamination.