Oil Question.....

[NOMARQUIS]

Can I run 5w30 in MM? The previous owner ran 5w30 Castrol Syntech in the car, however since I have ESP coverage the dealer feels I need to run the Motorcraft 5w20. Since I switched to Motorcraft 5w20, should I stay with that, or am I ok to keep what the 1st owner ran? If I have the dealer use my own oil at change time, I doubt they can say I didn't maintain my car if they have records.

[BAD MERC]

That's a judgement call. If you have a failure all they need to step out of liability is the wrong oil being used. Is it worth it?

[BirchMarauder]

I use what the dealer/manual tells me to use. the engine was designed with that oil in mind. just my opinion.

[RF Overlord]

NOMAR, to answer your question, yes you certainly can use 5W-30...

but...

I advise using what the manufacturer recommends while under warranty. Motorcraft 5W-20 is an excellent oil and using it will help avoid any warranty hassles should you ever have a lubrication-related issue.

[RR|Suki]

This is the same company that made LCMs that burn up at an alarming rate, made the axles from too soft a material so they get eaten away by their bearings, designed the window tracks badly and put in weak window motors hence the windows tend to bind, put heads on with only a few treads for the spark plugs, heads that tick, and puff blue smoke.... yeah trust their judgment.
That's not to say that 5w-20 is bad for the motor, but they went with it to squeeze a little more mpg etc. for the emissions testing. So go with what you feel good about, but this idea that "they designed it so I'll trust them" is not sound reasoning given the track record.

[Marauder386]

This is the same company that made LCMs that burn up at an alarming rate, made the axles from too soft a material so they get eaten away by their bearings, designed the window tracks badly and put in weak window motors hence the windows tend to bind, put heads on with only a few treads for the spark plugs, heads that tick, and puff blue smoke.... yeah trust their judgment.
That's not to say that 5w-20 is bad for the motor, but they went with it to squeeze a little more mpg etc. for the emissions testing. So go with what you feel good about, but this idea that "they designed it so I'll trust them" is not sound reasoning given the track record.


Just wanted to add the soft clearcoat/paint to the list of mistakes...


:cool4:

[fastblackmerc]

I run Mobile 1 5w30 in the summer and 5w20 in the winter.

[magindat]

The moral of the story is....

Motorcraft 5W-20 may not help your motor last longer, but it WILL help your warranty last longer!

[ctrlraven]

If the dealer is telling you that you need to use that to keep your warranty I would do just that. I've used it with no problem but I've also used Royal Purple 5w-20 and now using Amsoil 5w-20 XL.

[RF Overlord]

NOMAR, in light of some of the comments above, let me clarify my advice.

I meant that you should stick with 5W-20 during the warranty. Brand is irrelevant. The dealer cannot say that you have to use a specific BRAND of oil, I simply mentioned Motorcraft as it's an excellent value-for-money. Any other brand, especially one of the synthetics like Royal Purple, AMSOIL, Pennzoil Platinum or Mobil 1 would also be an excellent choice.

[rayjay]

I run Mobile 1 5w30 in the summer and 5w20 in the winter.

Excellent plan. I have run both weights. I have tried all the major synthetics. Mobil, Amsoil, Pennzoil, Royal Purple, MotorCraft semi synthetic. My particular MM prefers Royal Purple 5w-20. Runs best and gets best overall MPG. Problem is I have to order it in as I can not obtain it locally.

[Marauderjack]

How in the world are they gonna know if you used 5w20 OR 5w30??:confused:

I have used Mobil I for the biggest part of 196,000 miles with ZERO problems!!!:bows:

Use what makes sense to you....the motor won't have a clue!!:rolleyes:

[MERCMAN]

As we have our own resident expert here (RF Overlord), history has found that you CANNOT go wrong with his advice. As to how will they know if it is 5W20 or 5W30,,I am sure that FOMOCO has a lab that would put a C.S.I. lab to shame :rofl: