And another thing...
I also use single viscosity 30 weigh. From the engine class I took I was told the additives they add to oil to split the viscosity are bad for an engine, but not as bad as starting a cold engine with thick oil. Living in sunny southern California it doesn’t get cold enough to warrant a multi-viscosity oil. My Mercedes manuals shows 30 weight is okay above 32 F, and that only happens once or twice a year here. Plus the car is in a garage, the coldest it sees is 50 degrees.
5 speed '91 190E 2.6 320,000 mi. (new car, fast, smooth as silk six, couldn't find any more Peugeots)
5 speed '85 Peugeot 505 2.5l Turbo Diesel 266,000 mi. (old car, fast for a diesel, had 2 others)
5 speed '01 Jetta V6 (new wifes car, pretty quick)
5 speed '85 Peugeot 505 2.2l Turbo Gas 197,000 mi. (wifes car, faster, sadly gone just short of 200k )
5 speed '83 Yamaha 750 Maxim 14,000 mi. (fastest)
0 speed 4' x 8' 1800 lb Harbor Freight utility trailer (only as fast as what's pulling it)