Originally Posted By: asand1
Originally Posted By: Donald
Originally Posted By: asand1
My dad has always told me Pennzoil conventional was junk and always carboned up. He cited years of repairing and rebuilding engines ran on it.
His reasoning was that it was paraffin based and did not do well under heat.
Any insight to some history that might confirm this?
When was the formula changed?
How old is your dad?
59
59? He's still a young man. I am 76, and began driving in the early 1950's. In the 50's. I used mostly Sinclair straight 20 weight. No problems in a car that I bought new in 1954 and had 140,000 miles on by 1959. As the multigrade oils were coming into general use about that time, I began to use Quaker State Super Blend, and used mainly that brand until Mobil 1 came out and I began to us it about 1977.
I never had any problem with Quaker State, which was certainly a Pennsylvania crude, and never knew anyone who had a problem with it. Never saw any complaints about it in any of the automobile mags of the time. I still have a pretty large collection of auto mags from the 50's and 60's.
Since your dad is 59, he probably did not start a career as mechanic until about 1973 at the earliest. Engines from that era were as long lasting as anything made today. Most of them were on 3000 mile OCI's for severe service, and 7500 for easy conditions. In those days, I usually changed at 5,000 miles as a reasonable compromise. IMHO, any engine that was sludged up had not had timely oil changes.