I found this old post in my files:
I've been involved with and have tested synthetics since Mobil One first came out. I even still have an original metal can of Mobil One.
Anyway,
Synthetics are often misunderstood when compared to dinosaur oil.
First ones were tested by the same viscosity standards as conventional oils. Viscosity used to be tested by pouring a set quantity through a fixed orifice (Brix cup) and timing how long it takes to go through. Sort of like sand through an hourglass. Because the molecules flow easily, the time to pass through was less and they got a lower viscosity rating.
Old timers who thought heavier is better, decided the lower viscosity was a bad thing and shunned the expensive and runny Mobil One.
Mobil had to add thickeners to get the public to accept it.
Things have changed since then. Nowadays, you can get 0-20w oil and some manufacturers use it as an OEM spec.
Synthetics aren't new (Nazi's worked on synthetic fuel and oil technology during WWII), but it's taken a while for the general public to fully accept them.
Tips:
1. Choose a fully synthetic oil. I'm currently testing Pennzoil synthetic with Penzane. It's a substance developed for NASA for cold/hot extremes of space. Initial results look good.
2. Put aside pre-conceived notions of viscosity = protection. Heavy weight oil takes more power to pump. In sub-zero temps you can easily spin a bearing in it's bore with 50w.
3. Choose pump spring and clearances appropriately. Tighter clearances preferrable. Loose clearances need thicker oil to slow down internal bleeding.
4. Change oil/filter at same interval. Cost is higher for synthetics so don't bother using with a leaker or oil burner.
5. Synthetics are no contest winner in sub zero climates. 90% of engine wear is on cold start-up.
Leave a qt of regular oil outside (winter) or in the freezer over night and try to pour out. Now think about the pump trying to move that taffy to the bearings.
---Paul W.
Comments:
1. The best products are often more expensive BUT being most expensive does not guarantee it's the best product.
2. All major oil companies make synthetic oil. Look for "100% synthetic" on the label. A blended oil is cheaper and maybe a good way to try them out. If your engine doesn't like it then no point in going to full synth.
3. NO oil will fix a worn engine. If your engine is worn you probably should stick to cheaper conventional oil.
4. Synthetics are soluble in and compatible with conventional oil. You can use synthetics only in the winter and conventional in the summer if you want.
5. Synthetics can tolerate higher temperatures without coking. Excellent in turbocharged applications that have a pressure fed oil line to the turbo. Summertime ambient temperatures of 100+ degrees are still colder then engine coolant temperatures. If your oil temperatures are exceeding 240-250 degrees, then an oil cooler is a good idea.
6. I design my engines to work with synthetics. I select clearances, pressure spring, and oil pump to maximize benefit.
7. Even with all that the gains will be small. I've seen maybe up to a 6 hp gain on a 600 hp race engine, but realistically the street gains should be measured in Watts. Benefits include lower oil temps from reduced friction, easier cranking when cold, higher manifold vacuum, slightly better fuel economy (.5 to .7 mpg) and improved torque.
8. It's not nitrous. Don't expect a miracle.
9. Try the Pennzoil 10w-30 100% synthetic with "Pennzane". Subjectivly it seems better to me so far than the Valvoline or Mobil One. I could be just imagining the better driveability so I'd like second opinion.
---Paul W.
