But what vehicle? Weight of oil? Driving conditions? Highway, city? Interval? Every 6 months? 12 Months? 5000 miles? 12,000 miles?
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It may be better to go to a 50/50 mix year round... or dare I say...a full synthetic!
If you want a semi synthetic Motorcraft at Walmart makes a very good blend.
02 and 97 chevy prizm, 5w30, 50/50 city/highway, less than 4000 miles in six months,presently on a diet of castrol syntec blend,and they likes it.but have all this almost free edge and gtx, need to use it up.
I mix 5 quarts of GTX with 1 quart of Syntec. My Durango loves it!! 5w30 summer and winter. No problems at all. I am about to run out of PP for my Subie. It will get Syntec when that happens.