So I changed my oil today with 10w30 Castrol GTX High Mileage.

http://www.castrol.com/castrol/genericarticle.do?categoryId=82915476&contentId=7034438


I generally just use the regular Castrol GTX but I saw this in the store and thought I'd try it and see if I see a difference in the truck.

Anybody know what the heck makes this oil different from the regular GTX? Think it's a gimmick?

Regular GTX is conventional oil, while the GTX HM is a synthetic blend, so take how you wish from there...

Fellro said:

Regular GTX is conventional oil, while the GTX HM is a synthetic blend, so take how you wish from there...

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is that the only difference?

do they add something magic to the high mileage that makes it different than just calling it synthetic (other than $0.50)

I'm sure they have some seal swell additives and such. Synthetic is further refined, so it costs more to produce, so that would add to the cost to sell it for.

Synthetic blend?! It doesn't say that anywhere on the bottle! I'd think that they'd have to tell you if it's got synthetic oil in it... You sure about that Roger?

Last time I used synthetic my rear main started leaking 2 or 3 times as much as it was before I switched

Could've sworn the bottles we have at the store had that on them, guess not, but the additive package is the differences.

Tell me if you notice anything between oil switches.

One thing about my truck is that it doesn't leak oil...

It burns it though!

Ryan

I'll stick with RP

Skandocious said:

Synthetic blend?! It doesn't say that anywhere on the bottle! I'd think that they'd have to tell you if it's got synthetic oil in it... You sure about that Roger?

Last time I used synthetic my rear main started leaking 2 or 3 times as much as it was before I switched

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They do not have to tell you it has synthetic in it. If you had synthetic oil cause a leak then it must have been a very old bottle of synthetic oil. Modern synthetics have no compatibility issues, it was only the early blends.

As far as any "high mileage" oil the main difference is they add a ton of seal swell additives to the add pack to "in theory" help stop/prevent leaks in old high mileage motors. Sometimes it helps and sometimes it doesn't. More of a bandaid gimmick than anything else. If you can buy it for the same price as the regular oil then go for it, otherwise just save your money. In the long run the only thing that helps seal leaks, are new seals.


According to the MSDS both GTX & GTX High Mileage use "Highly Refined" base stocks, which generally translates into Group III or III+ which is considered to be synthetic.

http://datasheets.bp.com/ussds/amersdsf.nsf/0/C12CCB6BE0BEAF4186257307004F742C/$file/014214US-Lubes%20Americas-BP%20(Wayne,%20NJ%20US).pdf

http://datasheets.bp.com/ussds/amersdsf.nsf/0/315B032AD5BEFA9486257307004F86C5/$file/014232US-Lubes%20Americas-BP%20(Wayne,%20NJ%20US).pdf

www.castrol.com/castrol/displaysdst...uctName=GTX&languageType=3240&dataSheetType=1

blackhat620 said:

They do not have to tell you it has synthetic in it. If you had synthetic oil cause a leak then it must have been a very old bottle of synthetic oil. Modern synthetics have no compatibility issues, it was only the early blends.

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Did cause a leak-- just made an existing leak worse (my rear main seal, to be specific). Switched back to dino and it slowed back down.

Skandocious said:

Did cause a leak-- just made an existing leak worse (my rear main seal, to be specific). Switched back to dino and it slowed back down.

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Could have been caused by a couple of things:

1. Different additive package/formula than what you were using may have cleaned up some sludge/build-up resulting in a faster leak.

2. Since synthetic flows easier than most dino oils especially at lower temps, it would tend to leak faster through the same size hole than the dino you were using.

Just and FYI anytime you have a high mileage vehicle, changing to different brands or types of fluids can cause existing leaks or weak seals to behave differently. Just remember "Old Things" do not adapt to change well.

blackhat620 said:

Just and FYI anytime you have a high mileage vehicle, changing to different brands or types of fluids can cause existing leaks or weak seals to behave differently. Just remember "Old Things" do not adapt to change well.

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Yeah this advice was given to me beforehand and I chose to take my chances. It wasn't really a big problem-- just the difference of about 2-3 drops of oil every time I parked my truck. Switching back to dino made it better again so I just attributed it to being the fact that syn flows better.

LOL! Been there done that. Some times we just have to learn the lesson on our own.

blackhat620 said:

LOL! Been there done that. Some times we just have to learn the lesson on our own.

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You got it toyota One of those "I'll believe it when I see it" scenarios, lol!