Castrol Power 1 4T comes in 3 weights on our shelf: 5W-40, 10W-40 and 10W-50. Inside a single line the additive package is the constant and the viscosity is the variable, so this is a one-decision page — match the manual.
Priced by weight: 5W-40 from $21.17 for the 1 qt, 10W-40 from $22.12 for the 1 qt and 10W-50 from $21.17 for the 1 qt. 5W-40 is the cheapest way into the line and 10W-40 the dearest, a $0.95 difference — which is not a reason to pick one, since the manual decides that.
We carry 2 Castrol lines in total — Power 1 4T plus Actevo 4T. Power 1 4T is the dearest of them, opening at $21.17. Comparing across them is a fair way to shop; comparing a Castrol grade against the same grade from another maker is what the weight pages are for.
Bottle sizes in this line: 1 qt. All 3 are available now. Prices shown are ours and come from the catalog, not a list price.