NoLeaks2001

I couldn't get "search" working so I'll ask here;
My 2001 owners manual specifies 5-20 so when I did the first oil change when I bought this car at 25K miles, I used that (Motorcraft semi-synthetic).
I just heard on another site that the cars sold to middle Eastern countries (Saudi Arabia etc.) have 5-30 spec'd.
I am planning a trip or two to Vegas and parts North and East which involves travel through some very hot (115) and steep (Baker Grade,12 miles 6%) roads and I was wondering just how good this 5-20 Wt oil will hold up.
I was also wondering what the fleets use, taxi and police.
My last car had a 351C engine and I always used 20-50 Castrol and never had one problem in 220K miles (besides valve seals at 150K).I used to take that car across the desert all the time at 80 MPH.
Should I use 5-20,5-30 (or 10-30)? I'm sure that gas mileage will be off a hair,but I don't mind. Thanks-Brian

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2001 Grand Marquis LS, 30K miles mint. Finally a vehicle with NO LEAKS !

jwko

Personally I'm a 10w30 guy. With temps that hot that's what I would use.

Bert

We use 5w20 in all of our fleet. You could go to 5w30 in real hot climates but stay with the 5 lower number. The engines have some very tight tolerances and heavier oil won't get to the smaller areas when the engine is cold. The 20 does give better mileage, and that's why they specify that here. If you use a pump as we do to refill the engines, you can see how much slower the oil pumps, the heavier the grade.

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Bert

NoLeaks2001

Thanks jwko and Bert.

I decided to go ahead with the 5-20 Motorcraft Blended and just make any desert crossings during cooler hours due also to the fact that it has the original 10+ year old composite intake manifold. I'd hate to have that spring a leak out in the middle of the Mojave Desert on a 118 degree day.-Brian

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2001 Grand Marquis LS, 30K miles mint. Finally a vehicle with NO LEAKS !

Bert

My 2000 has the original manifold too. 154,000 miles and counting.

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Bert

NoLeaks2001

Now that there just made my evening. Thanks.

(because I've been told "you better just bite the bullet and get a new one on there" etc. The fact that yours is holding up is reassuring)

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2001 Grand Marquis LS, 30K miles mint. Finally a vehicle with NO LEAKS !

floater3

My 2000 owner's manual specifies 5W30. I wonder why they would make that change in the next year? I'm thinking the tolerances woudn't change all that much but maybe there is some other technical reason. As Bert noted, it's probably for the pursuit of the CAFE standards.

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'00 CV - 136K

NoLeaks2001

You're probably right on that.

I do notice though that looking at the spec sheet (Haynes for what it's worth) it shows the 1999+ engines got 40-70 psi oil pressure, up from the 20-40 psi of earlier versions,nearly twice the pressure.So maybe the engineers intended the higher pressure combined with a thinner oil to correct an oiling problem they were encountering such as insufficient lubrication at start-up.
Also in 2000 the piston ring side clearance and end-gap were tightened way up and the piston to bore side clearance '97 up was MUCH tighter (.0008-.0018 then '97 and later; .0002-.0010) which is a huge difference. -Brian

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2001 Grand Marquis LS, 30K miles mint. Finally a vehicle with NO LEAKS !