Castrol GTX High Mileage Synthetic Blend 10W 30

[Lymer]

I have an old Buick and have been using Castrol GTX High Mileage Conventional oil 10W30 since it hit around 120K mark. I need to do an oil change and went to pick up my usual Castrol GTX High Mileage brand and found they no longer seem to offer it as a conventional oil, but rather a synthetic blend seems to have replaced it.

My question/concern is can I change my oil and use my usual standard oil filter the same way with this synthetic blend as I would with the conventional Castro GTX High Mileage Oil. Which is to say when I do an oil change I drain out as much of the old oil as I can, but there always remain some with out a complete flush. Do I have to completely flush out the old conventional oil before using this New Synthetic Blend or can I just change my oil and use a standard conventional oil filter as I have always done with it.

Does this Synthetic Blend Castrol GTX High Mileage have a longer working life then the conventional GTX High Mileage I have been using

Thanks

 

[JC1]

Originally Posted By: Lymer
Do I have to completely flush out the old conventional oil before using this New Synthetic Blend or can I just change my oil and use a standard conventional oil filter as I have always done with it.


You've partially answered the question. Just drain the old and add the new. You'll never get 100% of the old oil out of your engine. Standard oil filter will be fine.

 

[TmanP]

I would think that the working life might be a little longer, but not much. Most High Mileage oils are blends- even if they aren't marketed as such. Don't worry about getting the old oil out, it won't hurt anything. In fact, it may be the same oil, just that they're calling it a syn-blend. Don't worry about it. The synblend is going to probably have a little lower viscosity at cold temperatures, compared to a conventional.

 

[Branson304]

You can just change oil as you usually would, no problem. Your filter is fine also.

 

[KCJeep]

Castrol HM has been a syn blend a very long time, maybe you didn't notice it before. Anyway no worries, the blend won't hurt a thing and in all actuality Castrol HM seems to be pretty light on the "blend" part of the equation compared to other syn blends, even Castrol's other oils.

I have used a lot of Castrol HM and it tends to run very quiet in everything I put it in. The Concorde is on a steady diet of it and when my Trop Artic runs out the Lumina will probably be back on it as well as it ran very well on it before.

Use with confidence, no worries.

 

[Lymer]

Thanks Gents

 

[Garak]

As for OCI length, Lymer, if you want more information, you'd have to give us a few more details about the vehicle, your usage pattern, your current OCI, and so forth. Also, a UOA would be your best best if you're really concerned. In any case, you've chosen a capable product.