can I use synthetic oil

[hotrodbob]

I used Mobil 1 fr ONE day. I lost 10psi of oil pressure and the engine had a lot of metalic noises. I refuse to use it again. I used AMSOIL in a H/Prod SCCA Austin Healey and we gained 5-10psi at race temps and had zero rod bearing failures all season. On dino oil we changed bearings after every race.

I run Castor syntec on mt V8 street rod and ran it in my Vette. never had a problem and picked up 2 mpg on the Vette over the dino oil. Castor is easy to get. Amsoil is hard to find, but is better.

GM recomended Mobil 1 in the Vette (late 80's).

 

[MustangSix]

Aside from being slipperyer, synth has better stability and flow characteristics at high and low temps.

If you operate in extreme environments you may want to consider them. They do not break down until much higher temperatures and at extreme cold they have superior flow .

I think it's a good safety policy. At 240F, dino oil is going to start going bad. By 340F, it's done for. OTOH, synthetics can probably survive that. Something to think about if you have a red hot turbo just sitting there after shutdown with oil still in the bearings.



Bob, your experience with Mobil 1 is not a common one I don't think. I've used Mobil 1 on a lot of engines and have never had a problem.

I've used Amsoil....good stuff, but not availble on the shelf. Royal Purple is great too. Both a little hard to get.

I'm still making up my mind on Castrol Syntec and some others like it. It is based on dino oil, but is so much changed and "reconstructed" that they feel justified in marketing it as a synthetic. It supposedly has the same characteristics of long chain synth oils, but is not quite the same molecularly. Lots of debate on that. My personal (cynical) opinion is it's a good way to sell oil at three times the price because you've chemically alter it a bit. :roll:

Next up, the great oil filter debate!

 

[hotrodbob]

I didn't realize syntec was not a pure synthetic. I prefer the AMSOIL, but like you said it's not an off the shelf product. When we first switched to AMSOIL from Dino oil on the Bugeye, we noticed that after the first practice sesion we had to readjust the idle down. We switched to sythetics in the diff and trans. WOW what a differance. The traditionally slow syncros of the Healey box were like new. We were able to pick up enough benifit fron synthetics that we could run down the back straight at Riverside with the F/Prod TR Sprites. I run the AMSOIL trans lub in my 2.77 box and it shifts like butter. At the time I ran MObil1 it was only available in 0w-30wt and that was just to thin. Shortly afterwards they came out with a more normal viscosity rating.

 

[Anonymous]

Plenty of arguments here:

http://theoildrop.server101.com/ubb/ultimatebb.php

 

[CobraSix]

True synthetics are hard to find now for one main reason...Mobil lost their lawsuit against other oil companies like Castrol and Pennzoil and such.

I'm excluding RP, Amsoil, Redline, and I'm only refering to common over the counter oils.

Up until about 1 year ago, Mobil 1 was the only true synthetic available at most stores. The others were advertising "hydrocracked" dino oils as fully sythetic since they had done some work on them. Mobil sued saying they could not call their oils synthetic. Mobil lost. Now I'm unsure of any oil company that makes pure sythetic because I think (though not sure) that mobil said to themselves "why make a synthetic when no one else is and still calling it synthetic?" I know they have a few still fully synthetic oils out there like their 0w40. When Mobil 1 lost the suit many Euro car owners were worried about Mobil not making high end synthetics anymore. Mobil also changed the classification (like SL, SJ, etc) of their 10w30 after they lost the suit, which leads me to believe it is no longer pure synthetic. 0w40 still has their old pure synthetic oil codes on it IIRC. I spent about 2 months researching this but once I decided to stay with Mobil 1, I stopped worrying about it.

I use the 0w40 for my Volvo, mainly because it is fully synthetic (to the best of my research) and because I live in New England. the engine is a small turbo charged engine and getting oil to the turbo at low temperatures is key as is the oil being able to maintain high temperature life because of the stress of the turbo. I use Mobil synthetic 10w30 on all my other engines with no complaints at all.

Remember, all of that does not apply to RP, AMS, Redline. As far as I am aware, their products are still purely synthetic.

Big advantage of sythetic, lower cost. You can extend the oil changes and it should also help reduce wear, especially at start up. Take my Volvo engine. When I bought it with 50k miles on it, it was using dino oil. After 3000 miles the oil would be ready for a change (looking at color as viscosity). When I went to 0w40 synthetic, at 5k the oil still looks okay and has good vicosity (looks like it could take about 1000-2000 miles easily). I just change at 5k miles to keep things simple and lined up with my service checks.

Slade