If you use 15w40 oil in them it will make the pressure too high. In fact, if you use 15w40 in the winter the pressure can get so high it makes the oil filter explode!

-J

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1991 350SDL. 230,000 miles (new motor @ 150,000). Blown head gasket

Tesla Model 3. 205,000 miles. Been to 48 states!
Past: A fleet of VW TDIs.... including a V10,a Dieselgate Passat, and 2 ECOdiesels.
2014 Cadillac ELR
2013 Fiat 500E.