2007 Buick Lucerne 3800 Series III 4.2k OCI 197k - unknown oil

[Danimal1q2w3]

My friend got a used car for a good deal! Changed the oil as soon as we got it and this is that UOA. Runs really strong

 

[himemsys]

Looks great! A little surprising for the existing oil in a used car, but awesome. How did you know the oil mileage?

 

[Danimal1q2w3]

Looks great! A little surprising for the existing oil in a used car, but awesome. How did you know the oil mileage?

Guy had a folder of records

 

[Duffyjr]

I wonder if it had 0/5w20 in it, I find it hard to believe a 3800 would beat an oil out of grade in 4.2k but I guess anything is possible.

Hope 5w30 was put back in.

 

[Danimal1q2w3]

I wonder if it had 0/5w20 in it, I find it hard to believe a 3800 would beat an oil out of grade in 4.2k but I guess anything is possible.

Hope 5w30 was put back in.

Mobil 0w-40 went in

 

[IndyFan]

The GM 3.8 is one of my all time favorite engines. Legendary longevity and reliability. My Dad had one in an Olds 88 and we had a bunch of them as company cars before he retired from GM. I always thought they felt stronger than they were rated on paper.

 

[Tkonrr]

The GM 3.8 is one of my all time favorite engines. Legendary longevity and reliability. My Dad had one in an Olds 88 and we had a bunch of them as company cars before he retired from GM. I always thought they felt stronger than they were rated on paper.

The GM 3.8 has a long piston stroke that makes the ample low end torque. That engine is extremely durable. The 4t65-e 4 speed automatic transmissions connected to it however do not hold up well under hard use.