What Oil Weight?

[Jaymus]

Guys, I just got an '86 Ford F-150 with the 302 V8 (fuel injected, since all '86 and above were FI) paired up with a 4-speed with bulldog. It has the 3.50 geared rear end, and needless to say, with this combo, I'm running pretty high RPM when running 55mph. This truck doesn't have a tachometer, but another one I drove was running 2700ishRPM @ 55mph. I try not to get over 45mph if no one is around me, but I don't hold people up because my truck is geared too low, either, lol.

This truck has 109,000 miles on it. Motor hasn't used a drop of oil and it doesn't smoke over the last 1000 miles.

I live in east Tennessee, and it is moderately hot in the summer. I don't know if humidity affects the engines cooling ability (I'd imagine it does somewhat), but it usually stays in the 90's during the day with high humidity. So it FEELS extremely hot, and also, 90's is pretty hot anyways. So, I was wondering if I should go with a 10w-30 for this engine (I'm not going less than that), or step up to a 10w-40? With high heat and, sometimes, moderately high RPM for a V8 to constantly travel, I wonder if I need a thicker oil?

I really need some ideas/opinions/answers here, as all this information on oil has turned me into an oil changing addict. I only want the best.

But, by best, I don't mean by putting amsoil in it, lol. I was thinking of running Castrol GTX 10w-30 or 10w-40. Will it hold up? I just don't want an oil that will get too thin on me in hot weather after traveling at higher RPM. My engine runs cool, though, and has no cooling problems. Even after running 60mph for 20 minutes or so.

BTW, the previous owner was the first and only owner, and he's taken great care of this truck. It's a beaut, and it runs perfect. Smooth as silk. It has a Kendall sticker on it, as if it has been changed somewhere at a shop. Maybe I should use some Kendall, although the only place I have ever seen it was on this site.

So, give me some advice before I have a heart attack.

 

[TallPaul]

If you're going 40 weight, might as well use a HDEO (Heavy Duty Engine Oil) like Valvoline Premium Blue, Shell Rotella, etc. These will be dual rated for gasoline and/or diesel like SL/CI. They typically come in 15w40 and gallon jugs. They will have higher zddp than PCMO (Passenger Car Motor Oil) which is good especially for your older truck.

Do you have a real oil pressure gauge? Look at the pressure hot at 2000 rpm. Should be bet 40 and 60 psi.

 

[Jaymus]

No, it's the oil pressure guage that says "NORMAL", lol. But, after warmed up and at idle, it stays around the middle.

I've read things on this site about those types of engine oils not being good for catalytic converters. Now, I do have a true dual exhaust with no cats and some flowmasters (for the sound) planned some day for the truck, but would that oil have any effect on the cats after even 50,000 miles?

And, are you talking about the Shell Rotella-T? Or another type of Rotella that is meant even moreso for gasoline engines, while also for diesel? I assume that whichever kind you are recommending isn't a synthetic? Or is all Rotella synthetic? Exactly which type of Rotella would you recommend? I realize that practically all the Rotella I have seen around here is 15w-40, but does it come in a 10w-40? This engine is far from worn out. I don't know what weight oil is in it, but it maxes at the end of the 'NORMAL' mark on start up. Keep in mind that this engine is only 109,000 miles and has been taken care of. But, yeah, I like the sound of using that oil if it's not going to have any negative side effects.

As much as I love Castrol GTX, I don't know if it would do perfectly fine, or if it would thin out too much after long driving in this hot weather at high RPM.

 

[TimVipond]

I'd stick with the 5W30 weight that Ford recommends for all temperatures, especially since it hasn't smoked or used a drop of oil the past 1,000 miles.

 

[teven7492]

Jaymus I would use Valvoline Maxlife 10w30 all year long second pick would be Havoline High Mileage . If you use a 15w40 your gas mileage will suffer and you will lose a small amount of horsepower.

 

[Jaymus]

Well, the book says 10w-30/10w-40 for the higher temperatures. Keep in mind that this is the 4-speed with bulldog type transmission. 4th gear is like a 3rd gear. 3.50 axle ratio. 55mph makes it tach pretty high. 55mph and above is where you feel that it's in the powerband, and it's holding it there. I know a 5w-30 or a 10w-30 would (should) be the same since they are 30 weights, but it's not the whole start up temperature concern as it is the weight (30 or 40) to use.

The only reason I'm wondering to go to a 40 weight is because this is the 302 V8 going 2700+RPM. I don't even KNOW if this is hard on it, it just 'seems' like it is. It seems like I need an oil to withstand those RPM in this type of engine, with this type of gearing, in this type of heat. I feel like whatever type of oil in it doesn't stay thick enough at sustained high RPM highway driving. The oil pressure goes down some after the high RPM driving, and even while high RPM driving for a sustained amount of time. That's mainly why I want to try a 40 weight, or a thick 30 weight. I can always give Rotella 15w-40 a try, and just see how it does.

 

[TallPaul]

I think Rotella T is the basic stuff. Good stuff.

Maxlife 10w30 is fine or even Maxlife 10w40. 15w better than 10w. 10w better than 5w. In both cases, all else equal, the higher w is a thicker, more robust base oil.

You don't get that cold in TN so no need for 5w anytime.

Get a real oil pressure gauge, they are about $17 at local auto parts. Easy install. Dump the dummy "gauge," which is an idiot light assembly. If you get better than 40 psi with 30 wt, no need to change. Maxlife 10w30 does well in my motorhomes on 5000 mile trips to and through Rocky Mountains, so should work fine for you. If oil press too low, say 30 or something, go 15w40.

I doubt HDMO will hurt your cats. They have been lowering the zddp recently.

 

[TallPaul]

BTW, what is a bulldog tranny? You mean a heavy duty manual with a granny gear?

2700 at 55 mph! My '95 F150 4.9L runs 2000 at 70 mph with the cheapo Mazda 5 speed stick and a 3.08 rear.

 

[Ramblin Fever]

Don't have the same truck as you, but I run 2700 at around 65mph, with a 3.9 gear ratio and typically use a 10w-30 with good results, even with running that same truck at 3-4k rpm's while climbing through the Rocky's.

In your neck of the woods, I'd run Rotella synthetic 5w-40 year-round; or Maxlife 10w-30 year round - both should do just fine.

 

[Jaymus]

Would you recommend Maxlife over Castrol GTX? If so, why? Does it have a higher cst rating at 212F? Is it better than, say, Castrol GTX High Mileage? Is Maxlife a synthetic? I don't know if I want to go to a synthetic on an '86 model truck. It doesn't leak any oil anywhere, and I don't know if a synthetic would start showing leaks up that didn't leak before.

And, yes, the bulldog is the 'granny gear'. I guess around here, people call it a 4-speed with bulldog, lol. It's not the 4-speed with overdrive, like some of them had.

 

[Merkava_4]

That 302 Ford is working awfully hard with those low gears and probably building up some heat too. Maxlife 10W-40 would be my choice.

 

[Ramblin Fever]

Maxlife regular oil DOES have PAO in it, believe 20%. However, it IS an oil based for higher mileage/older engines.

Maxlife synthetic is a group III oil, not a true synthetic, but purer, if you will, then say a regular dino or blended oil. But again, it is based around the needs of higher mileage/older vehicles.

Rotella synthetic - is a group III oil as well, this oil has a high amount of detergents and IS known for cleaning away gunk from older seals. I would personally use regular Rotella 15w-40 over the synthetic on a vehicle that old - didn't think of that earlier.

Castrol GTX has come a long way over the last 6yrs, when I first began using this oil in an Isuzu Rodeo, the truck seemed to burn it FAST. This truck was only 3yrs old at the time, and had never burned a drop of the Havoline. I then, switched it back to Havoline, and never looked back to Castrol....then.

We purchased a Tacoma 3.4L 6-months ago, and started running GTX in it 4k miles ago, and I'm impressed. Course, Toyota engines seem to be easy on oil, anyways, but it hasn't used a drop and is still very clean looking.

I will keep the GTX in this truck indefinitely at this point; as for the other truck, it lived on Havoline for it's first 149k miles, but I actually think it loves the Maxlife better.

Sometimes the engine makes the choice.

I've never tried GTX high mileage; but I have tried Havoline High mileage and it was a good oil too.

Personally, I think you'd be fine with a 10w-30; if you were hauling/towing, maybe a 40wt would be needed. But, honestly, I've never owned a truck that didn't pull 2-3k rpm's in normal driving, all of them ran Havoline 10w-30 as a staple.

 

[Jaymus]

I agree that if I can use a 30 weight, I'd rather use it. At least I do know that if I want to use a 40 weight, my engine is speced for it. Yeah, it would be best for towing, though.

The main thing about the 15w-40 Rotella is that it's a 15w. I wish it was a 10w. I don't guess it will hurt too much.

BTW, what is this PAO? I've seen it a lot throughout the forums. I'm pretty much down to choosing between Maxlife and Rotella, and also choosing between a 30 weight and a 40 weight. I almost think I'll go with the 15w-40 Rotella, just to give it a shot, and a Purolator PureOne, and see if that doesn't help keep my oil pressure a little higher after going 60mph/3000RPM for a while. I have great oil pressure when driving around the back roads, or just off the highway at 40-45mph and below, but sustained 55 - 65mph makes the oil pressure go down a slight bit, which I assume is from getting a little warmer than normal. I need to research Maxlife's 10w-30 and 10w-40's cst @ 212F, and also Rotella's 15w-40's cst @ 212F.

Then, I'll know more about the viscosity, but then, Rotella has an EXCELLENT add pack, making me lean more towards it. It would be a tough oil... very tough. This truck isn't purely a work truck, but it will be hauling loads of mulch in the bed of it (which really isn't that hard on it). I don't have a boat to pull with it or anything. Just my lawnmower and four-wheeler (450lbs), so again, nothing really to put a load on the truck. It's mainly just sustained 3000RPM on the 302 V8 that worries me. Gotta keep that viscosity up there. Maybe I'm just worrying too much.

 

[Merkava_4]

Quote:

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Then, I'll know more about the viscosity, but then, Rotella has an EXCELLENT add pack, making me lean more towards it.

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Better than Maxlife 10W-40? I'd be interested in knowing that answer.

 

[TallPaul]

Quote:

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The main thing about the 15w-40 Rotella is that it's a 15w. I wish it was a 10w. I don't guess it will hurt too much.

I have great oil pressure when driving around the back roads, or just off the highway at 40-45mph and below, but sustained 55 - 65mph makes the oil pressure go down a slight bit, which I assume is from getting a little warmer than normal.

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The 15w is definitely not a problem. Yeah, you might have a real pressure gauge without numbers. Does the needle go up and down some with RPM. If not then it is the dummy gauge, which tells you only that you have pressure above some set number like 9 psi, just like an oil light.

Maxlife is very very good. Has some PAO, which is a group IV synthetic (true synthetic), and has 300 ppm moly to help keep your engine it good shape.

In your climate I would be inclined to mix 20w50 and 10w30 Maxlife to create a Maxlife 15w40.

 

[Jaymus]

Well, here's some 15w-40 Rotella-T CJ4 (which I bought some for our tractor and tiller not too long ago). This is a VOA. http://theoildrop.server101.com/forums/s...ge=1#Post804388

Here is A 15w-40 Valvoline. I don't know if it is maxlife or what. If someone can fill me in on what type of Valvoline it is, I'd be thankful. http://theoildrop.server101.com/forums/s...ge=1#Post866576

So, what do you guys think about comparing them. The Rotella has 3000ppm of calcium. Both are nearly identical on viscosity at 212F. Seems like either oil would be a good choice.

Do those VOA's lean you more towards one than the other? I'm going to keep looking for some more VOA's of Maxlife and Rotella, either in 10w or 15w-40.


EDIT: Also, the Rotella has more Boron, but only in a small amount, and has little to no magnesium, where as the Valvoline is rich in magnesium. How is this relevant?

 

[TallPaul]

Both look good. The Valvoline is Premium Blue per the discussion.