I would like to see some opinions on this subject. I recently read an article with pictures comparing the heads off 2 Cobra's, one ran Synthetic from the start and the other ran regular. After 40,000 miles the difference is night and day.

I'm thinking about replacing both my engine and tranny oil with Mobil 1 Synthetic.

TIA

-D

 

I work in the engineering field for scientific testing and developing at one of the major auto companies and you would be surprised at the difference between regular oils and synthetics. Extreme heat and regular oil breaks down very quickly, the synthetics still have viscosity. In extreme cold the regular oil freezes, the synthetic doesn't. I changed to synthetic oil at 15 miles.

 

Synthetic doesn't change engine performance that much.

The real benefit of using synthetic over regular is that synthetic doesn't break down into sludge, which can build up and eventually kill your engine. If you use synthetic over the lifetime of your engine, and you maintain the other things on your engine, you can expect your cars life to be significantly increased. One of my buddies has a 1997 BMW 3 series with over 350,000 miles. He has had his transmission flushed every 20K and changed his oil ever 3 to 5K with synthetic. He has never required a rebuild or major work done on his engine or tranny.

As for the tranny, I would never use anything other than what is specifically called for by the manufacturer. Some manufacturers have a particular specification on their tranny fluids that have differing viscosities and friction. I remember Pat Goss of Goss' Garage talking about that last year when we discussed tranny flushes at one of his car care clinics.

Finally, when it comes to tranny flushes. Do them every 20K miles and you will reap the benefits. If possible, try to get a service department that acutally drops the tranny oil pan and plugs their flushing machine into the tranny rather than splicing into the fluid lines. Many garages say that you don't have to change the transmission oil filter but the manufacturers say otherwise. Also, you want to look at that filter and seem if you are getting any metal contamination (other than normal wear and tear) that may be the sign of something going really bad (like teeth shearing off a gear).

 

I actually asked the head service guy at Thousand Oaks Infiniti about synthetic. Since my dealer provides free oil changes for life, I asked if I could bring in synethic instead using the standard oil. He told that I really didn't need synethic unless I planned not to change the oil regulary. He told me that if changed it every 3k miles,the oil doesn't get chance to breakdown. I dunno, both my roommates use synethic in their cars but their cars are a chipped audi a4 and a chipped passat which they have to let their turbo cool down after driving hard. BTW, I will be schooling them both once my car breaks in

03 Black G35
Premium/Sports/Winter/Xenon/Aero

 

I don't wanna sound like a jerk but your service guy is misinfomed. Oil starts to break down the moment you start your engine. It's a very slow process but it does happen. The reason you change your oil primarily is because it gets dirty. The reason oil changes are no longer required at 3000 miles is because engine generally run much cleaners. However the oil still gets dirty eventually and the breakdown of the oil becomes a faster process as friction builds up and viscosity wears down.

Synthetic oil doesn't breakdown period. However, it still gets dirty and needs to be changed at the same recommended periods. If it doesn't, friction builds up and viscosity goes down from the contamination. However the oil itself actually doesn't breaks down. Synthetic oil CAN eventually break down but it's takes much longer and hotter temps.

Here is a link to a discussion forum that does a very good job of explaining synthetic oil and why it's better to use it.
http://www.allpar.com/eek/synthetic.html

BTW, IF you are not planning to keep your car more than a couple of years, then I personally wouldn't bother with Synthetic oil unless you are going to put that Z horsepower through it's paces every once in a while.

 

Synthetic, period.

I switched to synthetic on my max after 10k and 6k for my P5.

I will definitely go synthetic on my G35 Coupe at 1st oil change. That will be...... hmmmm. coming out at November + 5,000 miles...

99 Nissan Maxima SE-L
02 Mazda Protege 5
Coming soon..... 03 G35 Coupe.

 

My 99 Mercedes came with Mobil one, my 01 Vette came with Mobil One. I run synthetic Motul in mY Suzuki sportbike, Mobil one in my lawn mower, mobil one in a 46HP nissan Industrial motor. Mobil one in my Nissan SpecV, are you getting the point? I typically run between 6-10K miles, longer on the Benz, it holds 9 quarts, between changes based on the contamination that is mentioned by Sgt. Beavis. Its actually cheaper because I only change it every third time that you people are changing your Pennzoil/Quaker State.

 

Haha, I feed my lawn mower with Mobil 1 too! More convenient than getting those unknown 5W oil from your local hardware store.

99 Nissan Maxima SE-L
02 Mazda Protege 5
Coming soon..... 03 G35 Coupe.