I'm looking for peoples thoughts on this. The car (94 fd)has only ever had penzoil in it according to the original owner.. this isn't my brand of choice. Castrol GTX is. The thing is that I'm all for picking a brand and sticking to it.



What are your opinions on switching from penzoil to castrol,

 

Change away! Both are fine.

 

There's no problem at all with switching brands. I use GTX myself.

 

I also use GTX. I have heard that Penzoil creates a sludge like buildup when mixed with other brands but as far as swithching brands it is fine. I think this is more for adding oil because you are a little low and not to mix Penzoil with others. After a full change or two then there should be no more Penzoil in the car and you will then own a full GTX car.

 

I was told to use 10w-30 when I purchased my car. The origional owner told me it was the right oil to use for all weather, havent had any problems yet and thinking about switching to either Royal Purple or Redline, not sure yet though... doing my research.

 

buy the cheapest oil u can find and change it every 500 miles!!!

 

I reccomend that you flush the system befor you change types of oil.. You guys do have engine flush in the states right? If you do this it will keep prevent, problems between mixing oils.
J

 

I was talking to an automotive engineer last week, and he was saying that the one thing you never want to do is change the weight of the oil. The weight of the oil determines the amount of air the oil can absorb and how hard the engine parts need to work to move it and compress it and such. The more the air in trapped the more wear on the engine parts.