Looks like a lot of people have "switched" from the regular oil the cars shipped with to synthetic. From everything I've heard in the past, if a car starts with synthetic that's great, but switch to synthetic can cause blow-by, as the gaskets swell more with conventional oil, and once seated that way, a switch causes them to shrink. Anyone have any experience/opinions on this?
Thanks!

 

Valid questions, but you know those rumors that spread on the internet must perpetuate from someplace. What you describe is false. You can switch back and forth all day long with no issues to seals , or anything else. I only run synthetic in all of my cars (4000 miles a month). Once in a while if I run out and have some conventional I will toss that in but pull it out as soon as I pick up synthetic which I try to stockpile when on sale. Synthetics got a bad rap many years ago for items such as leaking, seals,etc.. but that was generations ago.

Too add, I actually have conversation with the reps from all of the major players often and this topic does come up once in a great while at trade shows.

 

Synthetic oil, personally, I’ve used it in all our vehicles for close to 25 years. There are numerous attributes to it, however primarily its use results in less friction in the engine, thus, providing better fuel economy, less engine wear, cleaner engines, etc. For cold weather areas, it’s great in the winter, as it never thickens. Interestingly, it is used exclusively in every jet engine!

 

I have used Mobile 1 15-50 since the 80's and have gotten over 300K miles out of a 944. 911SC, 1996 Jeep Grand Cherokee and a 1992 Chev S10.
Oil and filter every 5,000 miles. I buy it at Wal-Mart in 5 quart jugs for $23.

Another trick is to buy a vacuum pump for changing oil in boat engines. I use it to suck the automatic transmission fluid out (Usually 2 quarts, $9 each) and change it every other oil change (Redline synthetic). Never had a transmission problem either. Sure I don't get the pan off and change the filter but with new fluid all the time most of the dirt and praticles get sucked out anyway.

Here is the link to the vacuum pump. You can check any major boating supply house as that is how we usually get the oil out of our boats. I also use it to suck the brake fluid out of each line when it is time to renew the fluid.
http://www.pelaproducts.com/description.htm

 

I have used synthetic oils in my cars for years with great results. Recently I switched my wife's 2002 SC430 with 17K miles over to Amsoil 0-30W. I purchased the car in December and it had dinasour oil in it.

The oil has 3000 miles on it. It looks clean on the dipstick. Car is smooth as glass. We went to PA and back from NC and averaged over 26MPG at 80+MPH driving. Awesome mileage for a 300 Hp car. I use the synthetic for extra engine protection and the convenience of only changing the oil once per year. My wife only drives 5 miles to work so it is classified as extreme driving and I like the extra protection the synthetic will give me.

I will start converting the transmission over to synthetic as others have desrcibed in this thread. The pan will be dropped the first time. After that it's two quarts at a time.

People think synthetic is expensive but if you only change it once a year (15-20K miles) it works out to be cheaper than dino oil and you don't have the time investment or the mess.........

 

I still change my oil at the regular interval even with synthetic. I could care less about the extra $20 over the cost of a regular oil change when I look at the cost of a new long block! I dropped the pan on my 944 after 200K just out of curiosity and I was amazed. It had never had regular oil in it except when it was delivered. There was no sludge, no dirt no nothing on the inside of the pan. The oil just drained off and I had bare aluminum that I wiped with a rag and it looked brand new. That sold me.

 

108K miles on my 2002 SC430 and have always used Mobile 1. Change it every 5K miles.

 

What oil weight are you guys using? I was planning on using 5W-30 Mobil 1 Synthetic.

 

I have always used the 15-50 weight as it is thin enough when it is cold but on a really hot day with the air conditioner on it isn't too thin.
I actually think any of them will be just fine. I just have had great luck with the thicker oils. As the miles get added it is thick enough to slow down the blow by and I never have had to add any oil between changes.
I just remember a small block Chevy I had in the 70's and I used conventional oil but changed it every 3,000 miles. I had to do a valve job and the inside of the valve covers had about 1/4 inch of black baked on carbon that I had to scrape off with a putty knife. I know having that crap on the inside of an engine can't be good for it. I have never had any deposits using synthetic oil.
I don't use it to extend the oil change life. I change it per the manual recommendations or earlier. A little extra money every couple of months or a long block a few years earlier. Where would you rather put your money?

 

I am using Amsoil 0-30W in my wife's 2002 SC. Most manufacturers recommend a 5-30W oil for the vast majority of conditions. I like the 0W viscosity to help eliminate dry startups, since that is where most of the engine wear takes place. My theory with the thinner oil is that it will get to the parts faster as it will flow easier with the low viscosity. The oil is somewhat watery but as it heats up becomes a 30W. Best of both worlds IMHO.

 

1 vote for Mobil 1 5W-30.

 

If you can get your hands on Castrol 0W30 (some AutoZones have it), I would go with that. Amsoil 0W30 is also a winner. Barrring that, Penzoil Platinum 5W30.

 

I use Royal Purple 5W 30 in my LS and my SC. I love it

 

where do you buy royal purple?

 

all i will run is synthetic in all my cars