I bought my 1998 V70 last summer and the car is like new, it has 2.5 NA engine. After my first oil change which was M1 10w40 like I use in my red blocks. I noticed the car felt a little less peppy which I did not understand at the time. I do 3k change in all my cars, when I drained it I notice lots metal particles and silt in the bottom of the drain pan. Then it happened again with the next change. First I talked with my dealership shop forman who could not explain this. Then I called the station the lady used for the oil changes durring her ownership via the sticker on the windshield when bought. They told me they used full synthetic 5w20 in it durring her ownership. It seemed light to me but I complied and the metal in the drainpan has never come back, and it has been its peppy self and Idles smoother too. I have read on here that these cars must have W30 min and w40 preferred . Oh when the w40 was in it she raddled on start-up but starts quiet with 5w20 and has 128k now. I drive slightly hard on a car and this car likes to speed. I also drove it in a 1000 mile trip straight through both ways with no problem. So I can say 5w20 synthetic has not hurt mine at all. It stays on the full mark for the 3000 miles with no leaks. Just thought I'd share this with you out there.

 

That's odd, I would never try that. Those motors are high compression and I don't now if that matters.

I would check compression if I were you. That's the best indication of wear. I can't imagine where the metal was coming from and not have done harm. Going from 5w-20 to 10w-40 is a drastic change. Also doing 3,000 mile changes is a waste. That car should go 10,000 between changes with full synthetic. If I were you, I would send samples to Blackstone Industry for samples to check for the good change intervals. They will also tell you if you have metal etc., in your oil.

 

Oh no question, the drain pan had glitter and some shavings twice with 1w40 M1. Now back on 5w20 M1 oil comes out with no visable metal in drain pan and has been about 20k since the event. No knocks, strange sounds at all does not rattle on cold start which it did with 10w40. It reminded me of pulling factory oil from a engine durring break-in. Oil is cheep, and it was the original owners change schedule and weight. I just wanted to post that these cars do fine on light weight oil, but I would not leave such light oil in beond 3k down here in Florida heat. I noticed several questions have been raised about it's use in a white blocks and lots of fear that it would kill the engine at highway speed. I have driven mine on extended trips at high speed with no ill effect. In fact she effortlessly coasts down the road and wants to run 90. With heavier oil she felt sluggish, in fact the first time I changed it I could not imagine what I had done wrong. Usuially cars run better after a oil change, but this one did not. That with the metal in the 10w40 that came out made me call and find out what weight and brand was used originally. I was shocked when I was told 5w20 synthetic was used. I had never heard of that light of oil being used in a Volvo. She runs great on it and on a cold morning can drive a good 10 min before normal op temp is reached and almost endlessly if I have the heat on. We will see if the engine wears early, I am only at 128k and Osteen Volvo says the engine is in excellent condition.