What oil?

[svtvnm]

Just wandering what would be the ideal oil to use in my 99". Should it be fully synthetic or semi-synthetic and what viscocity?.

[RF Cobra]

My thought is, if you want the benefits of synthetic oil then you need to use a full synthetic. The semi still contains stuff you don't want. So, to me there is no real benefit for the added price over regular oil. You'll definitely be fine with Ford's recommended viscosity for your model year and climate with a full synthetic.

Originally Posted by svtvnm

Just wandering what would be the ideal oil to use in my 99". Should it be fully synthetic or semi-synthetic and what viscocity?.

[svtvnm]

My owners manual says to use 5w-30w that is the standard owners manual I don't have the COBRA owners manual is it the same?

[98 Yellow Snake]

Castrol Syntec 5w30 for my snake

[jlg32281]

A lot of people will point to endless studies showing one oil being better than the other. The bottom line is that any oil will do. Synthetic is a better lubricant, but conventional oils work fine. Unless you're a serious competitive racer, the fraction of a HP from using high end oils (royal purple, etc.) just isn't worth it. In all my years and many engines, I have never had engine failure due to oil failure. I've never even heard of anyone having such a problem. I use whatever is on sale, but I do use sythetic and yes you can switch without any problem. It might leak a little more since the synthetic molecules are smaller and can fit through smaller spaces. It will not hurt you engine or create leaks.

[nckissfan]

I use Mobil 1 5w30 full synthetic

[VenomSVT]

Originally Posted by nckissfan

I use Mobil 1 5w30 full synthetic

+1

[red04svtcobra]

Mobil1 is all I use.

[SuperG]

I used Castrol oil in my '93 SHO for over 200k miles with no lubrication related problems...insides still looked good. If you change the oil regularly, I think you should have no problems.

However, I use Royal Purple in both my Cobras' engine, tranny, and diff...

[pacificgreensvt]

royal purple, but its not cheap.

[Mystic_Cobra]

Originally Posted by jlg32281

A lot of people will point to endless studies showing one oil being better than the other. The bottom line is that any oil will do. Synthetic is a better lubricant, but conventional oils work fine. Unless you're a serious competitive racer, the fraction of a HP from using high end oils (royal purple, etc.) just isn't worth it. In all my years and many engines, I have never had engine failure due to oil failure. I've never even heard of anyone having such a problem. I use whatever is on sale, but I do use sythetic and yes you can switch without any problem. It might leak a little more since the synthetic molecules are smaller and can fit through smaller spaces. It will not hurt you engine or create leaks.

Please don't think I'm attacking you, I just want to clarify a few of your points.
Keep in mind that the more horsepower isn't the only reason to use synthetic. There are lots of other advantages. The oil doesn't break down as quickly, better detergents, etc. Sure any oil will do, but better oils will keep the inside of the engine cleaner, and minimize wear. Just because you haven't had a failure doesn't mean that there's no difference. Also, synthetic molecules aren't always smaller. They are of a more consistent size. Do a search on the web. There's hundreds of forum posts out there debating the issue. Look at some of the tests done by amsoil, for example. I use Mobil 1 synthetic. According to Amsoil's tests, Mobil1 gives you about 95% of the benefits of Amsoil for about 50% of the cost.

My car is ONLY used for road racing (it idles a lot cold during warmup).
One other note, there's a lot of debate out there bc many "Fully Synthetic" oils are now using part natural (dinosaur) oil base stocks with their synthetics to make the oil. Many think this is lying or cheating, or whatever. For me, it's about the performance.