Can you tell me what oil is better for my 4th gen. Hemi 5.7 09 Ram Laramie C.C I am using Mobil 1 full synthetic 5 w 20 and was wondering about going to semi synthetic same weight,is one a better choice than the other ?
Thanks.

 

Semi synthetic is pretty useless. Might as well buy regular oil.

Its pretty much regular oil or synthetic. I prefer synthetic myself, but regular is cheaper.

BTW, if you know you have a 4th gen, shouldn't you be putting your post in the 4th gen section?

 

Your gonna find a lot of opinions on this subject, but I prefer Amsoil. Been using it for years in trucks, cars and motorcycles. Its a little bit more expensive, but if you pay a little every year and get a preferred account you can order it to your door at wholesale. AND if you use the Amsoil filter you can go 15K between changes. My .02

 

check out the other thread currently running about my hemi burning through oil, may be helpful. I will be switching away from mobil 1

 

Yeah, md, I just read your thread on that, I am going back to Valvoline too.

 

Good choice!I now run Valvoline Synpower 5W-20.On the 2009 engine oil comparison chart,Valv. Syn is runner-up to Amsoil on wear protection.Actually,Valvoline has Mobil sued over not passing standard wear test.

 

I use Valvoline Synpower as well. I would caution those who drink the Amsoil "kool-aid" about extended service periods in a cylinder deactivation (MDS) engine. Any oil that achieves longer duty cycles by virtue of gaining viscosity over repeated heated/cooling cycles brings it WAY out of spec for proper MDS operation. Numbers I've seen dictate that Amsoil holds it's original viscosity to about 8k miles (6k in extreme/heavy use), and therefore should be changed prior to that time. Because of the cost of the stuff, I'd have a hard time paying for it and changing it at the same interval I would be changing oil that costs half the price.

This is NOT an attack on Amsoil, personally I feel it is a very good product, BUT the reason why it lasts so long is that it's viscosity actually gets thicker over time with use. MDS is VERY viscosity dependent.

As far as the OPs question, tests have proven that there is pretty much no benefit to using a conventional/synthetic blend over using strictly conventional oil. IMO, use full synthetic or just save the money and use a full conventional...

 

Excellent post and you make a very good point about MDS being viscosity dependent. I also think Amsoil makes good products - used their oil for a while in my BMW - but I would never be comfortable with the very extended OCI's they suggest are possible.

 

if it matters, i have been using penzoil ultra since my first oil change, and am changing at 6000 miles, no hemi tick or oil usage. also have been using a kn filter.

 

I have not heard this about Amsoil vs MDS motor, so in order to keep things factual and minimize false assumptions I emailed Amsoils Tech folks to find out if there was any facts to back up the above assertions. Here's what they had to say:

Scott;
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Sounds like an opinion, but is not factual. AMSOIL engine oil does not thicken (gain viscosity) in order to allow for longer drain intervals. If it did, that would be of concern as this MDS system does have very specific viscosity requirements. We have analyzed many samples of oil from these engines at different mileages, and have seen no thickening trends at all in these engines.
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Byron Selbrede
Technical Services