|Great Info, right from the horses mouth! My.... (archive)|
Posted by Steve Borsse on September 29, 1998 at 09:21:21:
In Reply to: Synthetic Motor Oil and Engine Break-in posted by XTech on September 29, 1998 at 08:26:52:
feeling is that as long as engine manufacturers hone the cylinder walls for ring pack seating, one should wait at least a thousand miles before putting synthetic oil in the engine. Redline must have solid evidence as to why you should wait, because why else would they deter the sale of their own products? I have great respect for Redline products and I put their 10W40 synthetic in my 98/2.8 at 2,500 miles. I now over an additional 4,000 miles on the car since then (which includes a high speed run to and from the
reunion), and the oil level has not declined even
1/16 of an inch on the dipstick! Bear in mind I'm talking about very hot summer weather in Florida. Which brings up another point.... I notice many of you are opting for higher viscositys such as 15W50. The same Redline engineer who answered your question talked me out of this. He strongly recommended the 10W40. I explained I was in very hot Florida, drove the car hard on occasion, etc., he said 10W40. I told him that all the years I've been in the hot south that I've only used 20W50 in all my vehicles, he said 10W40. Here's why:
1. The superiority of synthetics lies in the fact that a 10W40 synthetic can provide the high shear protection superior to a petroleum 20W50 in the bearings and cams, while providing a much lower viscosity on the cylinder walls and in the ring pack. The lower viscosity provides more power and also better efficiency and fuel economy.
2. Wide range synthetics such as 5W50 use the same thickener systems as petroleum 20W50 and suffer from the same viscosity losses in the bearings and cams.
3. Redline considers that in most cases an engine should not require the viscosity of a 20W50 and would be simply sacrificing power for doubtful advantage.
4. Redline 10W40 synthetic provides significantly improved film thicknesses campared to a 20W50, while providing the advantage of 1-3% more power!!
We all know how much we love extra power!! (: My mileage did seem to go up at least 1 if not 2 MPG. This however could be due to further "loosening up" of the engine. (I made on the way to the reunion 24.7-25 at 78 on cruise with air/lights/stereo/wife talking on. Before the oil change the mileage was about 23.)
The bottom line IMHO is that if you plan on keeping your Z3 (or for that matter any other vehicle) for any length of time, the switch to a synthetic motor oil is well justified.