Mixing M1 and Castrol Euro?

[Whitexi]

Im useing Mobil 1 0-40 and want to switch to Castrol Euro 0-30. I need to top off the oil for now so can I use the Castrol instead of the Mobil? Im thinking it will be ok since there both the recomended spec but just wanted to ask.

[llll1l1ll]

I've always been the old school kind of person so I generally do not recommend mixing oils of varying viscosity. Others may feel differently, but that's just how I am.

If you want to switch oils, but you also need to top off your oil, I would just go ahead and change it now with the oil you want. Then you will have the correct levels of the oil that you want!

[danewilson77]

You'll be ok until your next oil change.

[Whitexi]

I changed it about 3k it ago but my car is not liking the M1 any more and tendsto burn it off. I've read countless posts/ theads of people switching to the Castrol Euro and the oil consumption stopping or just about stopping. That's why I was going to use the castrol for top offs now till I change it in the spring. I was thinking maybe as the castrols used that it will slow it down also till its changed fully.

[echo46]

That's interesting, I've always had really good luck with the Mobile 0w40. Minimal burn off and can usually get a half decent price.

[telijah]

I thought burn off was normal on mine too, and was generally adding 1 quart between oil changes. However, I did an oil change right before getting a new clutch put in, and I had them replace the rear main seal as it was clearly leaking. I am literally about 500 miles from my next oil change, and my levels have been fine since the rear main seal being replaced. Even though I drive my car hard often, there has been virtually no burn off during this last oil change interval.

[Whitexi]

I don't think that is leaking but then again you never know. I thought that it was but then realized my VC gasket was leaking bad enought that it was runing down the back of the block. I checked a week after the VC gasket fix and it was dry, I will check that again though. Im hoping that's not the problem.

[telijah]

Well, the only way you'll know if the rear main is leaking, would be to look under the car where the trans and engine mate up and look for signs of oil there. I believe it would generally run down the trans case, but if it's a large leak, you would notice A: a big oil spot where ever you normally park, and B: lots of oil under the engine/trans mating area.

[Whitexi]

If I get time ill take a look today if not ill check it out this weekend. The last time I had the shields off there was no oil on them and the only spot I saw appeared to be from the top a bit from the VC gasket.

[Washburn]

Mixing of different brands and weights (grades/viscosities) is nothing crazy, esp. if you just want to top off. (and as long as they're both synthetic)