I bought my 1991 Buick Century 3.3L V-6 used with 80,000 miles. The engine was a "new" rebuilt engine since the original was damaged from overheating.
From 80K to 94K miles, I used Mobil 1 10W-30 and was not satisfied even though I thought I was using "the best." I had trouble with cold starts, and I live in Florida! When I tried to start the car, it was common that the car would not start on the first time. It normally took two or three more attempts to get the engine started. After the engine would start there was loud and prolonged clapping noises coming from the engine at an idle. Putting it in drive or driving long distances usually made that racket go away. The fuel economy was acceptable for the engine I had.
At 94,000 miles, I switched to AMSOIL 10W-30. I immediately noticed a dramatic reduction in starting times. Since switching to AMSOIL, my engine has only failed to start once on the first time, but one more attempt started the engine. After using AMSOIL for about 2000 miles, the lifter noise was almost gone and has gradually lessened even more. Fuel economy has also improved since switching to AMSOIL. I drive about 160 miles to school twice a week and used a half tank each trip. Since switching, I return home from both trips with about 1/8 of a tank left.
I am currently at 98,000 miles and I couldn't be happier. I am going to switch to the AMSOIL Series 2000 0W-30 on my next oil change
As a full-time unemployed student, I am saving money that is already in short supply and I get a strong sense of security from AMSOIL. I realize that if my car were to break down, it would have a dramatic impact on my education and finances. My use of AMSOIL has dissipated those fears and I know my engine is getting the best care possible. Through my use of AMSOIL, I hope to get many more miles of use out of my car, thus lessening the financial burden that I will already have from my school loans.
Saint Cloud, Florida