2003 Mach 1

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281
Location
Fallon, Nevada
Took delivery of a Torch Red 2003 Mach 1 5 speed back on July 25. 4.6 liter DOHC 305 hp v-8. I have been using 10w-30 Mobil 1 in both my Ford Excursion and F-250 SD Crew Cab, both with V-10 OHC engines. I wonder about this oil in the DOHC engine, or should I go with 5w-30. Can't bear the thought of using 5w-20 oil. I changed the factory fill out at 400 miles and put in Mobil 1 5w-30 with a new filter. Any thoughts? thanks...Ken.
 
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1,011
Location
Montgomery, Alabama
There is very little difference in the viscocity between Mobil 1 5w20 (a high 20w) and 5w30(a very low 30w). If you want thicker go to Amsoil 0w30 at 11.3cst which is middle/high 30w. I spoke to a gentleman at SDHeadquarters who happened to use 0w30 in his vette. He said it brought down his engine temperature 5 degrees over the Mobil 1 fill.
 

Jakebrake

Thread starter
Messages
281
Location
Fallon, Nevada
I decided to use Mobil 1 10w-30. I changed the original fill oil and filter (FL-820S) at about 400 miles to 5w-30 Mobil 1. Now at 2300 miles I have changed oil and filter again. At the current temps around here I am going to run 10w-30 Mobil 1 until it gets cold, then I will go to 5w-30. Thats how I handle my F-250 CC SD and my Excursion. Both of them have the 6.8 liter V-10 OHC engines. Oil pressure on the Mach 1 comes up right away, as it does on the other two vehicles, so I think I will be fine. And I don't think a whole lot of 5w-20 oils, or 0w-20 oils either. I don't feel that they have enough HT/HS for high reving motor such as in the Mach 1. Any thoughts? Thanks...Ken.
 
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5,358
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Gone
Jb, Probably in this case, "if it ain't broke don't fix it" is the best approach and just continue with what you are doing...but I would be REALLY tempted to test out an interval of M1 15W50 in those two V-10s IF you don't know of any construction aspects of those engines that would cause them to not "like" the thicker stuff very well.
 
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3,216
Location
BC, Canada
It is interesting that Mobil dropped their Delvac 15W50 and Chevron their synthetic (IV) 15W50 due to poor sales numbers. Lubricant viscosity requirement does not go up with engine size, but in the opposite direction more often than not. I'd bet that the various 20W50s, very popular at one time are collecting dust on store shelves while 5W40s are gaining momentium and may be taking over as the hot rodder's and motorsport choice. I don't think the 5W20s and 0W30s are selling well. Quite often the 10W40s are bashed as a VI improved 10W30. Does anyone think there would be a market for a low ash SL 15W40 PCO? Castrol GTX 15W40 ect, kinda fills the gap between 10W30 and 20W50 without going to a truck oil.
 

Jakebrake

Thread starter
Messages
281
Location
Fallon, Nevada
quote:
Originally posted by pscholte: Jb, Probably in this case, "if it ain't broke don't fix it" is the best approach and just continue with what you are doing...but I would be REALLY tempted to test out an interval of M1 15W50 in those two V-10s IF you don't know of any construction aspects of those engines that would cause them to not "like" the thicker stuff very well.
From what I understand the 6.8 liter V-10 uses oil pressure to set the tension on the chains that drive the overhead cams. Plus, since these motors start so quickly and rev right away to 1k rpm or more, it is beneficial that the oil flow come up quickly. Most of the people that are in the know that I have talked to about these V-10 modular engines don't recommend the likes of 15w-50 oil. I do like the idea of a 15w-50 Mobil 1, because of the HT/HS, in the Mach 1 because of the high rpm's that the motor is capable of. Still, I am not sure how that grade of oil will work in the 4.6 liter modular DOHC in the Mach 1. Anybody, please feel free to chime in...thanks...Ken.
 
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3,216
Location
BC, Canada
Sure....The HTHS values only come into play when the lubricant is very nearly over-heated beyond its service description. High shear typicals are necessary to prevent valvetrain damage in non-rollerized applications. Manufactures of late model passenger vehicles have gone to great lengths to eliminate "shear" in their new engines and in turn heavy viscosity engine oils to prevent damage in high shear zones are no longer required. Shear zones that have been reduced or elimated are the cam, lifters and rocker arms when the valve train is rollerized. The belt driven cam(s) and accessories. Better con-rod ratios to reduce piston side-loading.....can anyone think of a few more? [ August 11, 2003, 01:44 AM: Message edited by: userfriendly ]
 
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