一般不建議油品混合使用
車輛如出問題可能會有爭議
然而實際上不同的油品混何在一使用
並不會有問題,建議大大可上外國各大石油公司網站中的問與答來找答案
好像 API 美國石油協會中的甜甜圈認證中好像有相容性測試,建議可上API找找
http://www.api.org/certifications/e...ev-04-24-08.pdf

譬如 MOBIL 的問與答中有說到
http://www.mobiloil.com/USA-English..._Oils_FAQs.aspx
Can different synthetic motor oils be mixed together?

Mobil 1 is fully compatible with conventional motor oils, semi-synthetic motor oils and other synthetic motor oils, should it be necessary to mix them. However, it is important to note that the superior performance of Mobil 1 will be reduced by diluting it in any way.

MOBIL 全合成機油可與 (conventional motor oils)傳統機油就是礦物油,(semi-synthetic motor oils)合成機油,或全合成機油,相容混合使用,但是會減損其原設計之效能

CITGO石油的問與答也由提到
http://www.citgo.com/ConsumerProduc...ineOilMyths.jsp
Myth: You can't mix brands of motor oil.
Fact: Mixing brands is not the best practice because the additive systems in each may be different and when mixed may not function as efficiently as desired. However, no serious problems will occur if you must add a different brand of equivalent quality between oil changes. It is very important to maintain proper oil level.

不同品牌機油建議不要混合時用,會減損其原設計之效能,但是實際上卻不會有問題,重要的一點就是如要混合使用,一定要定期檢查機油量在規定的刻度,如有短少,請補足!


http://www.fpcc.com.tw/faq/faq_Eng_oil.asp
台塑石化也有提到
合成機油就是 PAO混礦物油而成

http://www.mobiloil.com/USA-English...09031410AA4cN3e


好像是一般不同黏度的機油,混合使用,如溫度超過 XW-40與XW-50
因高溫工作溫度不同 如超過 機油號數後面40的工作溫度時,40號數的機油會揮發掉
故要補充機油,建議您可上網找找資料!

提供您參考!