5w40 Rotella too thick for OHC?

[Black Thunder]

I was thinking about running the Rotella 5w40 full syn in my Ford T-bird with the 4.6 liter V8 and was wondering if this 40 weight would be to thick for an OHC.

Anyone else running this in a 4.6 or any OHC engine?

 

[Bryanccfshr]

I am running it in an OHC Mitsubishi but I am experimenting with differnt grades and I am trying to see if there is going to be a significant change in performance between differnt grades. Your engine will run fine on any engine oil. 5w20, 5w30 or 5w40.. but you may experience MPG loss. I have not recorded a gas mileage penalty in a 4 banger but my driving routine has been nearly all highway in a warm climate since I switched. My driving routine is changing since we moved into a new home and short trips are coming into the equation, I will be keeping an eye on the mileage. and addjust if neccesary.

 

[JTK]

I ran RT 5w-40 in my 2002 isuzu rodeo DOHC, direct acting valvetrain 3.2L. She ran as smooth as butter on it. Isuzu spec'd anything from a 5w-30 to 20w-50 on these engines & I had even run it on 5w-20. She lit off with the same force in temps below zero degF on RT 5w-40 as she did on 5w-20. I just traded the rodeo in, so either a dealer is going to dump perfectly good sump of 5w-40 + WIX filter, or some lucky SOB is going to get an anal BITOG'er vehicle!

G/luck
Joel

 

[Titan]

Blackstone has an interesting primer on this. They say too thick of an oil may result in increased valvetrain wear...tracable to specific wear metals that eminate from that area. They also say too thin of an oil may result in increased bottom end wear, again traceable with wear metals used in that area. Seems like "just right" is what is needed. Are you doing oil analysis to determine if wear metals are changing?

 

[C.S.]

I've been using RTS in my Probe GT's KL series 24V DOHC engine for almost 2 years, since just after an AutoRx treatment. This engine is kinda picky and is known for HLA clatter if everything is not spick and span. I get many comments on the fact that you cannot hear the engine running at idle. I won't use anything else unless they do away with it.

This is my DD, and I do short trips at home, since I live on a fairly small island. I also do several long distance trips each year - 800 to 1K miles - always at one sitting, i.e., stopping only for gas, a diet coke and a bag of chips, and the oil temp and pressure needles seem like they're painted in place, 210 deg, 47lbs. I don't know how I'd recognize a better oil for this engine.

I've always done 3K OCIs until the last two, stretching out to 5K; can't say I can tell any difference.

I don't know that you'd need a 40 wt in Wisconsin, though. I went to the 5W40 because we have several months a year when the daily temp is in the mid 90s.

FWIW, YMMV, EIEIO.

 

[JohnBrowning]

While many will say that it is not need in this engine it will work fine. Their are some UOA of this oil in Ford modular V8's. It will work just fine in OHC engine. Their are plenty of OHC engines both gasoline fueled and diesels that run 40Wt. oils or thicker with no problems at all. So feel free to give 5W40 a try and have no worries!!! I would recomend doing a UOA just so you can see how well it is working!

 

[racer12306]

i currently have M1 5w40 in my fiances 2.0L beetle, but with that being an unobtainium now. it will get rotella 5w40. the beetle seemed to love the M1 5w40 compared to a conventional 10w40. seemed a lot quieter.

 

[Black Thunder]

well being that it is winter yet and still snow on the ground it is still in storage.

I had planned to run Mobil 7500 (in it now) but due to the scarcity of it now in my area i've been wanting to change it to something more reliably stocked.

I've been looking at running a diesel HD oil in my explorer and i just recently pondered running the 5w40 in my car seeing that it is slighty under 4 bucks a quart.

the car would only be driving in the summer so freezing/startups wouldn't be an issue.

as far is Gas mileage dropping, would it be a significant drop?


I'll be sure to drop by the UOA section and peek at some results.

thanks for the comments guys

 

[Black Thunder]

i've also beening looking into running perhaps Castrol or maybe the recent-popular Pennzoil Plat.

 

[MNgopher]

I ran RTS 5w40 in my '99 F150 with the 4.6l for a year (three intervals). I've also run 5w20 and 5w30 over 1 year intervals and compared the numbers.

Statistically, there was very little difference between the 5w20, 5w30, and 5w40. The 5w40 gave marginally better results, but arguably the results are within statistical noise.

I did net a 5%+ fuel mileage drop over the 1-year period using 5w40, which is why I switched back to using 5w30. Note though that was over a full year, so it included winter periods that may have more of a bearing on the fuel mileage drop.

Whether the fuel mileage drop would be as severe in a car versus the truck, I don't know.

I came to the conclusion that runnign 5w40 in my 4.6 wasn't worth the fuel mileage penalty.

All my UOA's are posted on the board if you are curious.

 

[BrianWC]

40 weight oils are spec'd by tons of cars 4 cyls short of the 4.6l. I can't see why not. Realize you are getting a group III synth in Rotella and not a group iv ala M1 T&SUV. But I have some RTS sitting on my shelf right now waiting for my saab to tire of Pennzoil platinum.

 

[racer12306]

quote:

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Originally posted by BrianWC:
Realize you are getting a group III synth in Rotella and not a group iv ala M1 T&SUV.

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too bad the M1 5w40 no longer "meets" a gas spec. but also the rotella is cheaper than the M1 T&SUV was.

 

[Gary Allan]

quote:

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as far is Gas mileage dropping, would it be a significant drop?

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Depends on the cold (regardless of ambient) starts per mile (or miles/starts if you like). Short trip ..probably more. Loger trips ..hardly at all (or none).

 

[Bryanccfshr]

Gary,
Many 5w40's are now nearly as thin at 40°c as some 10w30's. That temperature is not far above ambient in the summer in many places.

I agree that the starts per mile will relate directly with mileage.

 

[Gary Allan]

Oh ..I mostly agree. The only real point I was making is that "heavier means less mpg" is usually (generically) limited to the warm up period. Beyond that (due to the time involved) ..you're usually encountering other forces that trump parasitic losses.

 

[Bryanccfshr]

No Argument from me.

 

[97tbird]

The various oil combinations and mixes I've run so far in my 97 Tbird OHC 4.6 definitely have been even thicker than the Rotella 5/40 oil's thickness (at least during summer time, I go a little thinner in winter months)...
It's doing fine at 112k miles now. so i guess if you want to use that oil it should be ok, at least for summer months.

 

[bar1]

Titan wrote: "Seems like "just right" is what is needed."

If the engine spec. is from 30w to 50w, a 40w would probably be "just right".

 

[cb4017]

I put RTS in my Jeep 3.7L OHC last oil change because I could not find M1 T&SUV 05w-40. So far so good. Runs quiet and I've not noticed a drop in gas milage.

 

[Titan]

bar1, I don't know if spec of 30 to 50 means a 40 is "just right". It could mean a 30 is just right, but, if you are stubborn, a 50 won't kill it. Or that a 50 is just right, but if you are stubborn a 30 won't kill it!

I really agree with Gary Allan. The shorter your trips (i.e., the more "cold oil driving" you do), the more likely the heavier oil will adversely affect your economy. If you are cruising at speed most of the time, especially if your crankshaft isn't whipping into the sump oil very much, heavier oils be less likely to adversely influence on your fuel economy.