Ive had my Greddy on for about 3 k miles. I did an oil change and have always used Castrol 20 w 50 down here in Florida. I just noticed on the other forum that guys are saying you must use synthetic with a turbo. I change my oil every 3 k. Is it really necessary to use synthetic?? Thanks

 

I would say yes it is necessary to use synthic oil. I will realy help the life of your turbo.

 

I haven't heard anything either way.

 

there were tons of turbo cars out there before using synthetic became popular. That said i use synthetic because it is better

 

I have Quaker State "Q" in mine right now, expensive stuff! However, I'll probably keep using it....

 

Well, I switched to synthetic back in my pre-turbo days because it went a few thousand miles further than dino oil before getting lifter tick (~3,000mi. for dino and ~5,000mi. for syn).

On top of that, it has much better high-temperature characteristics than most any dino oil. That's exactly the sort of thing you need with a turbocharged car. Lastly, every factory turbo car I've seen these days require synthetic oil, lest you want to void your warranty. I'd like to believe that says something.

 

I am one of those people that have not found any benefit in spending the extra money to use synthetic over dino. The only practical advantage I see in the synthetics is from thermal breakdown. That still would not be a problem if changing out the oil and filter every 4-5 K miles unless doing road courses every weekend or driving in extremely dusty conditions.

I still use 10-30 here in FL or sometimes use the Rotella 15-40 diesel for the high detergent and the point spread is not too bad. Still have nearly a full case of 10-50 and 5-40 synthetics won at various car shows. Just use those in my oil can cans for lubing power tools like the lathe, drill press, and both band saws. If anyone sees benefit from those oils can stop by and take the remainder for free.

 

Regular ole Greddy here but there is no question in my mind that synthetic for me is a must. That said, make sure you try a few choices(weights, brands..) out before making a definitive decision.
I've always used "premium " oils, no no-name brands or recycled stuff. I was finding that even with as little as 3000 kms that the oil was breaking down. Doing an oil change when the oil was warm would really exaggerate the difference. With dino oil, an oil change was made up of twno distinct oils coming form the oil pan. One, a watery, light oil, that poured out immediately, followed by a slow, thick oil, that took up to 20 minutes to ooze out. With synthetic, it comes out largely the way it came in. Intervals are still the same, but I feel much better with synthetic.
Now to throw a spanner in the works, but not all synthetics are the same.
I find that Redline is much lighter than its rated weight. My car simply drinks the stuff, I loose a quart every 500ks of 10W30. Syntec gets the lifter noise going after 2ks. For me its Mobil 1, but only 10W30. 20W50 just didn't flow well enough and kept the motor very noisy, especially the top-end.
In a pinch, Quaker State's synthetic does well as well.

 

Mobil 1 for me since ever since I've owned my first Miata, especially now that it is turbo charged. I feel that the extra lubrication/thermal requirements of the turbo make synthetic a must.

Dino oil is good for 3K of regular use, 3K of turbocharged miles are completly different miles in my book. The two Turbo books I have read are heavely biased toward synthetic.

Chris

 

Turbos have a tendency to coke conventional oil. The long term effect is failed torbo bearings and smoke out the exhaust. Synthetic oil is much more resistant to such issues plus the oil change intervals are longer. It makes more economic sense to use synthetic oil with a turbo car.
JMHO...

 

oils have come a long way in the past 10 to 15 years . the main advantage of synthetic is its lighter. The lighter the oil the easier it is on your rotating assembly. thats one way to get some free horsepower out of your motor .

 

I used to work near DART which is well known in the muscle car world for crate engines. They had a engine dyno there. I got talking to one of the testers there and we got into this type of discussion. He couldn't verify thermal breakdown, but he did tell me about dyno graphs of various oils in the same engine, on the same day, in the same temp, and same oil weight. Mobil 1 and Amsoil gained 5-6rwhp on a 500rwhp motor, where Castroll's syntec actually lost 2rwhp when compared to their dino oil.

 

Synthetic is cheap insurance. Why would you save a couple of bux on the off chance it could end up costing you a lot of money down the road.

 

i was thinking of using syntehetic too, but my mechanic friend told me to use regular oil for breaking in the turbo, i dunno why lol

simon

 

hi simon. stop resurecting threads. okay. thanks.

Only said this because he has done it about 8 times

 

Im glad he did Im doing an oil change this weekend. Still havent decided whether to use synthetic or not. But my Castrol really does look watery and burnt after 3k miles

 

oil's cheap, even synthetic.

motor and associated parts aren't.

 

use synthetic for what you get for the few dollars more spent its worth it

 

+1 It's a pretty cheap safety measure. Also, recommended by Corky Bell himself (or regular dino oil with more frequent oil changes). Granted Corky may not be right on everything, but he probably has more experience than most of us combined so his opinion weighs a bit more than most.