Nah, you can use Royal Purple if you'd like. I was a diehard Royal Purple guy, but the latest I read was the Royal Purple is still using the same old formula, but Mobil1 has been making theirs better. With RP costing almost $9.00 a qt and M1 costing $7.80 a qt, I switched to Mobil1.

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- Brian


1989 500SEL Euro
1966 250SE Cabriolet
1958 BMW Isetta 600