Castrol gtx syntec vs. high mileage gtx syntec

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Mar 25, 2009
Hi guys i am fairly new here and need some advice. I have a 1973 international scout II with 345 V8 rebuilt motor 10 years ago but only 15,000 miles on the motor. It only gets run a few times per year. I was using castrol 10w-30 gtx synblend and was very happy with the results. However i am currently not employed and would like to save some money. The Synblend runs almost $7.00 per quart at oreillys auto the (only place I can find it). However at walmart I can get the high mileage castrol gtx synblend for only $17.00 for 5 quarts. That is quite a nice savings! But I don't want to ruin the motor in any way as it does not have high miles..... I was thinking since it is a older style motor the tolerances aren't as tight as new motors so the high mileage oil might work well in it...... Do U Guys have any opinions experiences, I would appreciate it...

You can pick up the syn blend for $17 at walmart for 5qts (FLAPS take you to the cleaners for oil prices compared to big box stores). If you HAVE to cut money to save on an oil change you would be better off trading or selling it honestly.
Use Supertech HM if money is that tight. You will get a quality product that fits your vehicle and save some money in the process.
Thanks guys, I am really happy with the castrol line of oils in these motors specifically. It has solved a few oiling issues common to a IH v8. I have 3 of them so it adds up. I was really wondering what the difference is in the high mileage castrol oil vs. regular gtx syntec blend. It says on the website the gtx syntec gives the best overall protection but they also state that in another way for the high mileage stuff so it leaves me confused as to the difference.

-P.S. walmart does not carry it in 10w-30 for gtx "syntec blend" or I would buy it there. they have 5w-30 I believe which won't work......

The Castrol synblend at Wally's is the Dexos rated version and is a superior oil to Castrol HM which is barely a blend, not that you'd have problems with either. Running the Castrol Synblend in one of our vehicles now and like it well enough it will also be the next fill.
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