Just got my '06 S40 back from its 105K miles check at the dealer I bought it from new. I always tell them at the previous checks not to change the oil 'cause that's one of the things I do myself & they always comply. Buuut, this time I forgot to tell them & since they have a new service advisor he didn't know me to check on the oil change. Sooo, even thought it's never had anything in it but Havoline 10-30W, they put in Pennzoil semi=synthetic 10-30W. Iv'e driven it about 75 miles since the change. Should I drain it out & go back to my usual or should I leave the new stuff in there? It's never used/leaked a drop in the past. Thanks for your opinion.

Cal

Those cheap buggers!! Your car wants to have full synthetic! It came from the factory with synthetic.

No harm done, just wait until you normally change the oil and go back to full synthetic.

Klaus
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Volvoless. Its been 90 days. BUT I am getting a 1966 122 soon.

Thanks, but I should have made clear that all I've used is regular dino Havoline. And it's run just great, like I said no problem with leaks or usage. Figured if dino's OK for Irv Gordon it's OK with me!

Irv runs a 4 cyl cast iron block, and he runs it! You have a 4 cyl aluminum block with an oil cooler. I doubt you ever get the oil very hot to prevent sludge buildup which will cause considerable damage as the engine gets older. Remember, antifreeze will get much hotter than engine oil.

Use full synthetic, all the time. Otherwise your PCV breather will get clogged and the seals will start blowing out. Then you can reduce the flush interval to 5-6,000 miles instead of every 3K.

Klaus
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Volvoless. Its been 90 days. BUT I am getting a 1966 122 soon.

Irv runs a 4 cyl cast iron block, and he runs it! You have a 5 cyl aluminum block with an oil cooler. I doubt you ever get the oil very hot to prevent sludge buildup which will cause considerable damage as the engine gets older. Remember, antifreeze will get much hotter than engine oil.

Use full synthetic, all the time. Otherwise your PCV breather will get clogged and the seals will start blowing out. Then you can reduce the flush interval to 5-6,000 miles instead of every 3K.

Klaus
--
Volvoless. Its been 90 days. BUT I am getting a 1966 122 soon.