Oil change interval - 986 Forum - The Community for Porsche Boxster & Cayman Owners

saaber · 01-22-2008, 02:06 PM

Quote:

Originally Posted by PhxRealtor

They insisted that it had to be done at 3,000-5,000 intervals regardless of what others and the manual say (I'm sure they love doing $200 oil changes). They used Mobile 1 10W-30.

That mechanic is just flat wrong!

First, the weight is wrong. Factory fill should be 0W40 Mobil 1. I prefer something a bit more shear stable so I am currently using redline 5W40. In hot AZ I would go a little heavier such as Mobil's Delvac 1 5W40 or redline 5w40 unless this could void your warranty (if applicable). Note that most people who have concerns about Mobil 1 0W40 are critical that it is too thin (it shears). So this bafoon is saying to go even thinner in hot Arizona? Yeah, that makes sense.

Second, the interval is way off. Your car has a huge oil sump. 3k miles is ridiculous. This has been discussed at length and you will find that people in the know recommend 7500 - 10,000 miles. For my 00' car, my used oil analysis at 8700 miles on Mobil 1 0W40 showed that the TBN number (additive package indicator) was 1/2 of starting TBN (which to many is an indicator that it is time to change the oil). Also the oil had thinned to a 30 weight. Thus if using Mobil 1 0W40 I would go 7500 miles ideally or up to 10,000 miles if you wish. Most Porsches have been using the 15k interval with few oil related engine failures so the 3k is just wasting money (or earning money if you are the repair shop). I think the 10k or 7500 is safer than the 15k interval.

Porsche's official recommendation at the moment is 12k for the 2001-2005 cars and 20k for 05+ but I have had many mechanics and service writers tell me 10,000 max. It has been rumored that after the introduction of the direct injection engines that the official recommendation will be 12k for all years. My point being that 3k is way too low.

My suggestion would be to find a new mechanic ASAP that knows something about Porsches. Sorry to be blunt. You are doing the right thing by asking questions and not just letting them take you for a ride. Good show!