please recommend for Ford lightning

[rikenco]

Hello. I purchased a Ford lightning last week. It has 104,000 miles on it. It has been modified somewhat with a 6# lower pulley, ported blower, Ford racing heads, intake etc. The previous owner had it dyno tuned and it puts out 410hp and 480tq at the wheels.

The previous owner is a Ford service manager at a dealership. He gave me all the service records and I noticed he had been running 15w-40 Diesel oil in it at every oil change. Cold idle pressure was pushing 80psi, warm it was about 55psi. It was time for an oil change and I bought mobil 1 15w-50 on sale and changed the oil. (the previous owner said it was due for a change). The Ford owners manual states 5w-30.

In the mean time, I emailed mobil, motorcraft, royal purple and shell. Each one replied that the 15w-40 Diesel is great oil for HD gas applications. All suggested though that I go down to 5w, or 10w 30 or 40 because the oil pressure would run too high on the 15w-40. So essentially my question is, which? Does the motor being modified make a difference in which weight? I have also heard that you shouldn't use a syn in a supercharged vehicle. I mentioned that in the emails. All of them said that syn would actually be preferred. That may be sales talk, I don't know. Any advice appreciated.

 

[spasm3]

rotella t-6 5w 40

 

[Ben99GT]

I would run Red Line 5W-30, Amsoil HDD 5W-30, German Castrol Syntec 0W-30, Mobil 1 10W-30 High Mileage, Mobil 1 0W-40, or Royal Purple 0W-40, something with a HTHS viscosity between 3.5 - 4.0 cP and fairly low volatility. JMO...

I can't find the Rotella T6 product data sheet, but it will probably work great too.

 

[Durango]

If the owners manual says 5W-30 then use that weight. Despite the info you received I'd use the most inexpensive synthetic you can get in your region.

Durango

 

[Ben99GT]

While the truck will probably be just fine on your run of the mill 5W-30, this truck has stepped well outside of stock Lightning power levels. Stock Lightnings produce 310-330 rwhp depending on whether it is a '99-'00 or '01-up.

 

[3311]

Continue using 15w40. With those mods and the amount of miles on it, the 15w40 must be doing a great job.

 

[rikenco]

So I suppose a compromise would be a full syn 10w-30? What I mean to say is, if I used that, I wouldn't be necessarily hurting anything. The previous owner/modifier/Ford tech, said that 15w-40 Diesel was a "machinists secret" in a gas powered 8/10 cyl. Pretty confusing.

3311: I posted before I read your advice. I am tempted. Apparently it never hurt him. Another of my issues is that we are going into winter soon. I'm in the KC area so you never know. It could be 65 degrees in December, January, or -15. Iv'e seen both and everything in between. Worried that a 0w-5w would be too light in normal weather and that 15w would be too heavy for winter.

 

[3311]

Rotella(semisyn)10w30 t5 at walmart with a Motocraft filter would probably be a great combo for you if you want thinner.

 

[Ben99GT]

Originally Posted By: rikenco
So I suppose a compromise would be a full syn 10w-30? What I mean to say is, if I used that, I wouldn't be necessarily hurting anything. The previous owner/modifier/Ford tech, said that 15w-40 Diesel was a "machinists secret" in a gas powered 8/10 cyl. Pretty confusing.


It depends on the 10W-30, some 10W-30s run as thin or thinner than 5W-30s when warmed up.

A good off-the-shelf 10W-30 for your truck would be Mobil 1 10W-30 High Mileage. Not regular Mobil 1 10W-30, but High Mileage because of the HTHS.

Compare:
M1 10W-30 High Mileage: http://www.mobil.com/USA-English/Lubes/PDS/NAXXENPVLMOMobil_1_High_Mileage_Oil.aspx

M1 10W-30: http://www.mobil.com/USA-English/Lubes/PDS/GLXXENPVLMOMobil_1_10W-30.aspx

This should bring down oil pressure versus a HDEO 15W-40 but offer more than enough protection for your engine.

 

[panthermike]

Originally Posted By: spasm3
rotella t-6 5w 40


That would be a good compromise IMO.

 

[mechtech2]

The advice by the major companies to go down to a 5w, 10-30 or 40 does not make sense.
When hot, the 15-40 is the same as 0-40 , 5-40, or 10-40.

 

[dparm]

He's in Kansas. It will get cold there and I think 15w40 would be pushing it.

There's a TON of good 5w30s out there. Since this thing is not stock, I'd suggest something decent like Red Line or Amsoil. Get the oil analyzed at the 5k mark and see how it's holding up.

 

[shpankey]

Originally Posted By: Ben99GT
I would run Red Line 5W-30, Amsoil HDD 5W-30, German Castrol Syntec 0W-30, Mobil 1 10W-30 High Mileage, Mobil 1 0W-40, or Royal Purple 0W-40, something with a HTHS viscosity between 3.5 - 4.0 cP and fairly low volatility. JMO...

I can't find the Rotella T6 product data sheet, but it will probably work great too.

I like the cut of your jib. I'm with this guy. Excellent recommendation's here.

 

[Durango]

Originally Posted By: rikenco
So I suppose a compromise would be a full syn 10w-30? What I mean to say is, if I used that, I wouldn't be necessarily hurting anything. The previous owner/modifier/Ford tech, said that 15w-40 Diesel was a "machinists secret" in a gas powered 8/10 cyl. Pretty confusing.

3311: I posted before I read your advice. I am tempted. Apparently it never hurt him. Another of my issues is that we are going into winter soon. I'm in the KC area so you never know. It could be 65 degrees in December, January, or -15. Iv'e seen both and everything in between. Worried that a 0w-5w would be too light in normal weather and that 15w would be too heavy for winter.


rikenco,

I'd go ahead and try a full synthetic in the 10W-30 weight catagory as you mentioned. I won't hurt to try it and see the results although I still believe you should stay with a 5W-30. To go heavier will compromise your MPG even more. May I suggest Quaker State "Q" synthetic. It cost a little less than a Mobil 1 of the same weight. Good luck

Durango

 

[dparm]

He's driving a supercharged pickup truck, I doubt fuel economy is very important...

 

[panthermike]

A 30 or 40weight would suffice here, use whichever you'd like. IMO, the MPG difference between a 5w30 and a 5w40 would be VERY small. I know all cars are different, but take my old '00 Corolla as an example. Most often I used 10w30, but also 15w40 and 20w50(an attempt to curb consumption). MPG was always consistent in that car.

Again, I know not all engines are the same.

 

[OVERKILL]

M1 0w40 or Ben's recommendations. Another suggestion would be Delvac 1 5w40, but the 0w40 is "closer" to your factory weight, while being designed to be run in very high power density European engines with forced induction from the likes of Porsche and Mercedes.