M1's response to oil recommendation

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Sep 12, 2002
I asked if I can use synthetic oil from the start on a 2003 5.4L SOHC V8, here's their response:


You must use the 5W20 motor oil if your owner's manual recommends it. Mobil1 0W20 motor oil will be available in March 2003 which will be approved for all 5W20 vehicles and you can switch over at this point.

Anyone have any synth blend/synthetic 5W-20 oil analysis to show that it can handle abuse???
i bet it will be able to handle the abuse as long as you don't race your truck everyday. Heck, i rev my civic up to 5500 rpms a few times a week(not all the time, mostly shift at 3000 or 3500 rpm). Ill be using it when im due for my 3rd oil change since i have to change my oil next week and ill be using the 5w20 castrol gtx and the bosch premium oil filter!!!
Wow, an honest answer from an obvious car nut at Mobil1!!!


The Windsor motor is considered by many experts to have a slight advantage in build quality compared to the Romeo built engines.
Ford decided to switch to the 5W20 motor oil to meet CAFE requirements because of all the SUV's and the big Excurssion that they sell that get worse fuel economy than a GM truck or a Ferrari. Ford's research and development found out that they can use 5W20 motor oil in most of their engines to get better fuel economy while not sacrificing engine protection. Personally if your owner's manual says you can use the 5W30 motor oil without voiding your warranty I would use it for the added heat stabilty.

What I heard from reliable sources was that the 5W-20 will keep your engine running as long as the manuf wants it to run

Still I'd like to see some long-term analysis on used 5W-20 from racing and what not...

I appogise for the tardiness of this replay. The following paragraph was provided by one of our technical serice advisors.I hope itwill adequately answer your question.

"Vehicles that recommend SAE 20 grade oils ( 5W-20 or 0W-20 ) are specifcally designed to operate using these thinner / higher fuel efficiency/ higher power oils. Because these viscosity grades are lighter ,they provide less drag and provide greater efficiency..

In vehicles where these oils are recommended , OEM's have provided metallurgy suitable for these viscosities and have also provided metallurgy finishing to reduce asperities ( hills /valleys) you normally see on a metal surface under high magnification.

Although there may be vehicles that could use a 5W-20 or 0W-20 viscosity even though it is not the recommended viscosity grade, I would recommend that you stay with the viscosity grades recommended by the OEM for your Vehicle."

Don Turk
J. Donald Turk
Global Lubes Public Affairs Advisor
Phone: 703-846-1395
Cell phone: 703-819-9306
Fax: 703-846-4169
Pager: 888-520-2642
Email: [email protected]

[ January 20, 2003, 06:05 PM: Message edited by: tenderloin ]
Sorry but that's total fuc*ing bullsh*t

pardon my French of course.

Why is this BS?

2000 Ford Mustang GT: 4.6L SOHC V8, made in the Windsor engine plant. Uses better build quality along with retaining rings to hold the piston wrist pin in place.

2000 Ford Crown Victoria: 4.6L SOHC V8, made in the Romeo facility. Uses slightly lower build quality, uses pressed pins for the pistons.

1998 Ford Mustang GT: 4.6L SOHC V8, also made in the Romeo facility.

2001 Ford Mustang GT: 4.6L SOHC V8, made in Romeo facility.


prior to 2000, all of these cars used 5W-30.
All of a sudden in 2001, Ford wants us to use 5W-20. The engines were certainly not changed to REQUIRE 5W-20. I do not see any changes in the metallurgy or bearing clearances that would warrant 5W-20. The experts that work on modifying these engines also agree that 5W-20 is not mandatory.

Exxon Mobil is just spewing out crap that Ford and Honda wants them to spew out. That's why synth oil companies like Redline are making their 5W-20 or SAE 20 oils to meet the new market demands.

Mobil 1 was smart in giving a real response. They're making the 5W-20 and want to make money off of it, but the smart tech person actually has hands on experience with a vehicle (mustang actually). Turk from Exxon seems to be a run of the mill customer service rep guy that knows jack about cars.

Yes 5W-20 might be an excellent oil but I just don't see a legitimate reason to use it OTHER THAN FUEL SAVINGS (as slight as they might be).

I'll continue to use 5W-30 in my 2000 4.6L SOHC V8, and I'll use 5W-30 in my 2003 5.4L SOHC V8.

5W-30 and 0W-30 have better thermal stability than the lighter weight 5W-20.
Yeah right Chevy also recomended that I use 5w30 in my old 4.3 TBI S10. Think I ever used that stuff once I learned something about engines? no Start with a 10w30 oil and if it gets hot in your area find a good 15w40 for summer use. The triton motors have never impressed me with durability, and they are also famous for high oil consumption (particularly the 5.4 and V10 with is same thing with 2 more cylinders). Think Ford recommends 5w20 for use in the 03 Cobras with their 390hp supercharged 4.6?? I think not. If they do, they are WAY too afraid of CAFE and the EPA. If CAFE had it their way motor oil would turn into WD-40 specs then engines wouldn't last at all, and then they'd come out and say the internal combustion engine is junk and all they do is pollute the air and excesively use natural resources such as oil. Ignore Ford and Exon and use a good 10w30 dino oil for break in then switch to M1 10w30 or even Redline of the same viscosity. When mileage gets past 60k or so upgrade to a xw40 for summer use.

Ooops I contradicted myself, just stick with a good 10w30 oil year round. After mileage gets up upgrade to a 15w40 for the summer if it gets hot where you live.

Durability problems with the modular motors? Since when?

Mustang owners run 5W-30 on the drag strip all day long.

Police Interceptors run 5W-30 all year long.

Vans, trucks, etc... all have modular motors (except for PSD and 4.2L V6s) - I've never heard of durability issues.

They're easy to maintain (spark plugs on the top part of the engine, right on top), 5 second Thermostat changes, easy to access belt, alternator on top (no charging problems), EXCELLENT brakes, etc...

GM trucks, OTOH, took 7 spots out of the 10 vehicles in the world that guzzle the most gas. The other 3 were taken by Ferrari.
Well on a more on-topic note...

is there any reason to run 5W-30 in a OHC engine?

I mean, if 10W-30 can be used year round - then why use 5W-30?

My operating temperature ranges from -10F to 100F ambient. I have a 2000 Ford 4.6L SOHC V8, a 1981 Ford 302 V8, and a 2003 Ford 5.4L SOHC V8.

The 4.6 is in a Crown Vic, the 5.0 is in a T-bird, and the 5.4 is in the E-250.

Right now I run 10W-30 in the 5.0, but I was not aware that 10W-30 is the preferred oil for the 4.6 and 5.4 - given that the 10W might make it slightly thicker than I'd want for an OHC engine especially during startups in the cold. I.e. -5F to 0F.
As someone who works in the auto industry I can easily say with no uncertainty that the move to xw20 oils was driven be CAFE and nothing else. As some one else has mentioned the engines have not changed.

Yep I keep saying that the 2000 4.6L SOHC V8s and the 2001 4.6L SOHC V8s did not change enough to warrant the use of 5W-20, if anything the GTs should be using a slightly thicker oil due to the fact they went from PI-head Windsor blocks to lower quality PI-head Romeo blocks.
mebanditws6, I have 2 of those modular motors that supposedly consume a lot of oil and are unreliable. That is simply not true. I have a 2000 supercharged 5.4 Lightning and a 2001 4.6 Mustang GT. I broke them both in the same way by changing the original oil and filter at 500 miles, running havoline 5W-30 to 1500 miles and running Mobil 1 5W-30 TS and then SS ever since. Neither of these engines consumes any noticable amount of oil in 3000 miles. Neither one of these engines has any reliability problems. The Lightning went in the shop for a wiper recall and an intercooler recall, though mine never leaked. The Mustang has never been in the shop and has had 0 problems and 0 recalls since purchased in June 2001.
I also have two of those supposed oil eaters, (4.6l triton V8's in my F150's) both of which are on an exclusive diet of 5w30. The '97 doesn't use any and it has 156,000 miles on it. My '99 with 81,000 miles uses a quart every 4000 miles, which I would hardly term "excessive".

I also have an 88 Chevy 1/2 ton with over 250,000 miles on the odometer and the 4.3l V6. Guess what - its used 5w30 for nearly its entire life and it runs just fine. 1 quart every 3,000 miles, same its done since new.

Sounds like a bowtie boy to me...
I have something from each of the big three and they all have their quirks.
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