It is time to change the oil and my Blazer and I was wondering if High Mileage Oil helps the engine in anyway. It is 4.3 liter with 120,000 miles on it and the compression of all cylinders is with 16 psi of each other. There is currently a small leak at the rear main and it has used about a 1/4 of quart of oil in 2700 miles. Any help would be appreciated.

 

Most fully sythetic oils will do just fine but those high mile oils are not synthetic I believe but if they are synthetic than go for it.