Quote:
Originally Posted by OkieRover
That's the oil my wife's Taurus calls for.
I think I put 10w30 in it last time.
She only drives it around town. It's a 2002 and just now has 48,000 miles.
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5W-20 is, in a sense, different than other viscosities. The difference is that the primary OEM manufacturers that specify the use of 5W-20 (Ford & Honda) established a very stringent proprietary rating for the 5W-20 oil used in their cars.
Ford and Honda together dominateed the market for 5W-20. So, the oil industry responded. The just about any 5W-20 is significantly better quality base stock than what can be easily found in budget 5W-30, 10W-30 and especially 10W-40.
The ASTM test sequences that are required by API for the other oil are run "double time" for any 5W-20 that meets Ford and Honda requirements. This is at least as big a deal as it sounds! The sequences that other oils endure for 60, 64 or 80 hours, are run for 120, 128 and 160 hours on the
Ford/Honda approved 5W-20.
Group I base stock is still common in 10W-40 oil. It still can be and is used to make 10W-30 and 5W-30. But I don't think it is possible to meet the Ford/Honda specification with a group I base stock oil. From everything I've read and heard, anything meeting the Ford/Honda 5W-20 spec uses at least a group II base stock and most also blend in some even better oil(group II+, III, III+, IV) with that to meet the stringent Ford/Honda requirements. It may be possible to meet the spec with a group II base stock, no other blending oil and enough additive.
Any 5W-20 that meets Fords WSS-M2C153-H
http://www.ilma.org/resources/ford_2004_my.pdf
spec is a product of the kind of high quality that most people would associate with the term "blended synthetic" but the term itself is not very meaningful. It is the WSS-M2C153-H rating that is meaningful. API SL rating does NOT indicate that a 5W-20
meets the Ford WSS-M2C153-H standard so it is advisable to
verify that any 5W-20 does meet this spec.
5-20 costs little more then 10-30, and its a better oil.
