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Reply to "New Car Warranty using Amsoil..."

Originally posted by Captain Kirk:
Originally posted by ADFD1:
Thanks my question is if a 20 grade oil is spec'd and used and the engine fails because the oil was too "thin" "CAFE" as you said who eats the repair? Not in Kathy's case just a general question?


If ford,or some other MFG determines the oil is too thin and is leading to damage,then ford would be on the Hook. However,they will try to weasel out,if the consumer gives them an out.

I can't believe ford has spec'd 5w-20 for a if a 5-30 would harm fuel economy?

The mustang V-8 in some cases is spec'd for 5w-50(I believe synthetic only),so what gives with the V-10?

I would think on long hard hot runs with the V-10 running 5w-20, the oil would thin out too much and lose pressure at certain locations in the V-10 engine without triggering the oil pressure sending unit,and wipe out a bearing or more.

There apparently have been many issues with this engine all over the net,and lots of warranty work,haven't really researched the fine details though.

I would run 5w-30 at least,and use only synthetic.

5w-50 for the stang is here.



The v-10 has a different crankshaft design from the v-8s. It uses a split throw on the rod journals for even firing(bad idea)and is drilled differently for rod bearing oiling. A fully groved main bearing would provide a 100% increase in oil volume to the rod bearing,but they dont use one.They could do alot better. There are alot of racers using 0-20 and producing over 1000 horse power with the 4 valve v8 without bearing problems. Most would probably like to use heavier oil but pressure to the valve train is not regulated.This will cause the hydraulic cam followers to pump up in the early 4 valve heads and hold the valve open if thick oil is used. That would be bad. Thin oil bleeds off faster and allows this engine to rev to over 9000 rpm,without bearing problems. Later high performance modular 4 valve engines use a miniature hydraulic cam follower with a higher bleed rate that allows heavier oil to be used. They spec 5w-50 in that engine.I dont know if the bearing clearance have changed for the supercharged engines , but all modular ford are a select bearing fit engine,meaning they fit each engine with the exact size bearing required to get the clearances perfect. 5w-40 full synthetic would be my choice for A motorhome with a v-10.