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Which is better?: Motorcraft 5-20 synthetic blend, $17.97. Walmart 5-20 FULL synthetic, $17.47

Would FULL synthetic allow less internal engine resistance resulting in better fuel mileage?

Thank you.

One of the perceived benefits of syn oil is slightly better mileage. Try both, keep detailed records of mileage and let us know.

Full synthetic is, theoretically better then a blend. Car oil change interval extensions are based upon using full synthetic from synthetic base oil and not blends. So, assuming that the full synthetic is from a reputable manufacturer, that gets my vote.

Either is fine as long as you change the oil per Ford specs. If you want to extend the interval, you not only need fully synthetic oil but need extra additive compounds to prevent acidification of the oil.

Full synthetic, always. The synthetic blend is like Claudia Shiffer’s body with Susan Boyles face. A poor compromise.

I have the same dilemma. The car is a Mazda CX-9 with a Ford Duratec engine that calls for Motorcraft. I have extended warranty, do my own changes and keep receipts. I can not see them declining warranty for using synthetic, but I guess it is an excuse that could be used.

How do you judge that one motor oil is better than another?? What yardstick do you use? Hearsay evidence from people who have rigid brand loyalties? People who tell you what you want to hear?

Which one of your “life mobiles” are you going to use it in… oh hell never mind you probably have your mind made up already. And talking to a wall is useless.

Full synthetic is better

As long as you don’t buy it at Walmart, who is the most rabid anti-Union employer on the planet

Get it on sale at Costco

I would be hesitant to buy a 0W20 synthetic BLEND! Go for full synthetic and make sure it matches the exact spec called for in the owner’s manual. There is more to oil than viscosity.

The blend is 5W20; in my case, that is what the manual calls for and hope that is also the case for the OP.

Gee, the semi-syn Motocraft 5w-20 is the oil the manufacturer specifies just for this application. As such, I think it’d be more than adequate for the manufacturer’s service interval; heck, the manufacturer’s service interval was probably designed around that oil!

Walmart’s house brand (Supertech) is made by Warren oil, I believe…at least the conventional oil is. I have no problem with Warren/Supertech: my only issue is that, going forward, the supplier of “Supertech” is no doubt subject to change; “whoever can do the job cheapest” being the Wal-Mart way. This means that the exact specifications of Supertech brand oil are somewhat variable. I’d have no problem with that in a bargain-priced conventional; it’s enough in that case that it meet the API S(whatever) rating. For a “premium” product, however, I know I wouldn’t be happy with perfomance specs that change.

For the exact case of Motorcraft 5w20 vs. Supertech 5w20 syn, I’d opt for the Motorcraft at the same price. Given the opportunity to make other choices, I’d be inclined to go for a 5w30: same cold flow, but more protection against thinning at high temps, given OP’s known tendency to run at triple-digit MPHs, from time to time. I think 20-weight is largely a CAFE fiddle; they’re likely quite satisfactory for most applications and uses, but they don’t do anything “better” than a 30-weight, and you at least give up some margin of error in the event of oil overheat/fuel dilution/viscosity shear. They (per FoMoCo) earn them 0.4% better MPG, which is important to a company operating in today’s regulatory environment. I, OTOH, have no pressing need to “green-nose” anybody, and the peace of mind of running a slightly heavier oil is well worth the 0.06 MPG I’m not getting.

(Although the Ford Modular motor is known for lasting practically forever in adverse conditions, so I think we’re all overthinking this. Any API SN oil, in a viscosity remotely close to that specified, ought to provide for an engine that’ll still be going strong as the rest of the vehicle is ready for the crusher.)

Ford manual recommends Motorcraft 5W20 synthetic blend.
Walmart just came out with 5W20 full synthetic. Before it was only 10-30 full synthetic.

I would do fuel/mileage calculations, but emergency transports, with more firm accelerations and higher speeds, completely ruin my gentle efficient driving fuel-mileage figures.

Either will be fine. I’d probably go with the Motorcraft, but that’s just personal preference. Theoretically the full synthetic would get minutely better fuel economy, but in the real world it probably wouldn’t be noticeable.