synthetic vs premium

[brainrn]

I have a 92 f350 460 7.5l v-8 with 198000 miles. I have had it since it was new and regularly change the oil at 3000m. I found that motorcraft no longer makes premium sae 10w30 motor oil and used synthetic 10w30 for 3 or 4 oil changes. I heard that was bad so I switched to high milage castrol gtx sae 10w30. My recommended api was SG. Any thoughts? Did I make the right choice? Thanks.

 

[HTSS_TR]

Motorcraft is semi-syn and is very good quality oil. Since your truck is about 200k miles, any high mileage oil may be better for your application.

 

[heavyhitter]

I would use the Motocraft synthetic blend before I would use the High Mileage GTX. There is a VOA of the High Mileage GTX on here and it has a surprisingly weak add package especially for a High Mileage oil.

Welcome to BITOG!

 

[tig1]

Originally Posted By: brainrn
I have a 92 f350 460 7.5l v-8 with 198000 miles. I have had it since it was new and regularly change the oil at 3000m. I found that motorcraft no longer makes premium sae 10w30 motor oil and used synthetic 10w30 for 3 or 4 oil changes. I heard that was bad so I switched to high milage castrol gtx sae 10w30. My recommended api was SG. Any thoughts? Did I make the right choice? Thanks.


As long as your engine isn't an oil burher or leaker the synt. is a good choice for you. Simply put, you were told wrong about synt. Try Mobil 1 High Mileage 10w30 and extend your OC out to 7-10,000 miles. No problem.

 

[Ken2]

The API service category SG in 1992 has been superceded by SH, then SJ, then SL, and now SM. In a year or two we'll have a new service category superceding SM (SN?). If the same engine was built today, its manual would call for SM, and it would be way out of date in 17 more years.

There is no special reason to use Ford's Motorcraft oil. Nothing wrong with Motorcraft and nothing special about it. Use any good brand of oil you'd like.

As tig said, if you got good results with synthetic oil, no reason to switch. You'll like the result in the winter, especially if you use 5w30. Or, use any brand of 5w30 in the winter and 10w30 in the summer. Oil is much better than it used to be in 1992.