15W40 for Toyota Tacoma 2.7

[nanney]

Lots of posts reporting good things with these diesel oils. Temps in my area of North Carolina are currently in the 70's during the day dropping to the high 30's overnight. Should only get warmer from here on until September. My local shop carries Mobil brand 15W40. I assume this is Delvac? Anyone think this is a good choice for my 2.7 four banger? Possible to run year round? Temps rarely drop below the 20'sF and we don't see single digit temps but maybe once or twice(meaning one or two days total) per year. Some years not at all. Currently running 10W30 Havoline dino with 5K OCI. No oil consumption and the color goes from light golden to light brown. Truck has 129,300 miles. Plan to do a UOA at 130,000 and change. Should I go ahead with the 15W40 or stick with the 10W30 until I get the results back?

 

[jthorner]

I like the 15W-40 for engines which call for heavier oils, but if Havoline 10W-30 is working brilliantly for you then why change? John

 

[Jelly]

quote:

---

Originally posted by nanney: Lots of posts reporting good things with these diesel oils. Temps in my area of North Carolina are currently in the 70's during the day dropping to the high 30's overnight. Should only get warmer from here on until September. My local shop carries Mobil brand 15W40. I assume this is Delvac? Anyone think this is a good choice for my 2.7 four banger? Possible to run year round? Temps rarely drop below the 20'sF and we don't see single digit temps but maybe once or twice(meaning one or two days total) per year. Some years not at all. Currently running 10W30 Havoline dino with 5K OCI. No oil consumption and the color goes from light golden to light brown. Truck has 129,300 miles. Plan to do a UOA at 130,000 and change. Should I go ahead with the 15W40 or stick with the 10W30 until I get the results back?

---

I agree with John, but if you want to change, then by all means go right ahead. I see the main benefits being reduced varnish and deposit accumulation, less blowby, and a quieter running engine as well as having better protection in hard running and having the ability to extend the drain intervals. I run HDEO 15w-40 year-round here in Kentucky (very similar temps in comparison to N.C.) with no problems. Had one 0F day last winter, and while the truck did turn over very slowly (4.3L V6, C1500 Chevy), I had absolutely no start-up noise, indicating that at least if virtually no fluid film was present, the "heavy duty" barrier additive package of the HDEO's was doing the job until the hydrodynamic film could be established. I use Pennzoil Long-Life because of high consumption in my truck (factory standard bad valve seals! ), but for you, I'd recommend Mobil Delvac 1300S...great base oil and great additive package, with cold pumping properties that are superior to those of other common, mineral-based, HDEO 15w-40's. Delvac didn't reduce consumption in my truck, be did BIG TIME in my girlfriend's Volvo I5 though... Go over to Wally-World and spend $6/gallon instead of going to a shop...

 

[nanney]

I guess after the reading I've done on this sight, I'm starting to think that a 15W40 would be better for the summer temperatures. What are the limit temps on a 10W30 before you need to go to a 40W. Summer temps are always in the high 80's with low to mid 90's common.

 

[Amkeer]

Why the thicker viscosity? It seems that the 10w30 has gotten you this far why would you want to change? If things are working good then stick with what you are doing otherwise you could cause problems. If you really want to change then go with Delvac 5w40. Daily Drives: -2003 Toyota Tacoma PreRunner XtraCab, 2.7 Liter , Mobil1 Synthetic SS 5W-30. ODO 8350 Miles. -1995 Toyota 4-Runner 3.0 V6, Mobil1 Synthetic SS 10W-30. ODO 84500 Miles. http://community.webshots.com/user/amkeer

 

[Motorbike]

quote:

---

Originally posted by nanney: I guess after the reading I've done on this sight, I'm starting to think that a 15W40 would be better for the summer temperatures. What are the limit temps on a 10W30 before you need to go to a 40W. Summer temps are always in the high 80's with low to mid 90's common.

---

The 15w-40 in any brand is just huge overkill for your engine and ambient temps . I have pointed to a trend analysis before where a Ford Escort engine operated in Florida heat had less wear metals when the owner dropped to a 10w-30 motor oil from the 15w-40 " same brand ". Most all gasoline engines in good condition will react similar and additional fuel mileage will be observed with the lower VI oil with NO loss of engine protection .The fuel milaege gain comes at no additional cost The breaking point for most engine makers is 86F for 10w-30 dino's unless your running Mobil Supersyn then you can use their 0w-30 , 5w-30 and 10w-30 at temps above 86F instead of stepping up to a 10w-40 dino per Mobil . A couple of makers of the new PAO 5w-40's even state that they do not recommend the use of this wt in smaller OHC Import engines and that is not CAFE related . I wish the recommendations of using a 15w-40 HD Fleet oil with Diesel engines as the prime category this stuff is made for in everything under the sun would die out . There are always better alternatives than these diesel oils for modern engine designs and if in doubt call the oil makers and see what they have to say . No kidding , a phone call to any of the oil makers will mirror what I've said many times . A nod is just as good as a wink to a blind horse though .

 

[TallPaul]

quote:

---

Originally posted by Motorbike: I wish the recommendations of using a 15w-40 HD Fleet oil with Diesel engines as the prime category this stuff is made for in everything under the sun would die out .

---

It seems to me that an oil pressure or temperature gauge would be good here. If the vehicle maintains good pressure and/or temperature using 10w30 then I don't see a need to move to a 10w40 or 15w40. As for 15w40s I find it frustrating that they are mostly (nearly all) made for (targeted to) diesel/fleet applications. I am going to use a 15w40 this summer in my pickup, which needs the 40 for better oil pressure, but the 15w40 I am using is probably the only passenger car motor oil 15w40: Valvoline Durablend. It is not loaded up with heavy duty motor oil levels of additives. I just don't believe the passenger car gasoline engine application really needs all that extra additive package. Anyway, my two cents. [ April 17, 2004, 08:47 AM: Message edited by: TallPaul ]

 

[Motorbike]

Paul Nanney wrote : Currently running 10W30 Havoline dino with 5K OCI. No oil consumption and the color goes from light golden to light brown. Truck has 129,300 miles. His engine appears in good condition still w/o need for an oil pressure guage and no real need to change brands or viscosity . So , I agree with you that these engines do not need these larger additve packs for the most part with reasonable intervals and your analysis bears this out but..... you ran a 10w-40 through winter when analysis showed you a 10w-30 Maxlife run would have been fine and w/o need to run a electric heater near the oil pan and now you are planning on running a thicker oil than the 10w-40 Maxlife ? Analysis is a tool one can learn from ...please think about what your recent analysis taught you [ April 17, 2004, 09:20 AM: Message edited by: Motorbike ]

 

[n8wvi]

Why not make everyone happy (those that think 15w-40 is too thick and those that want a HDEO) by running something like Pennzoil LongLife 10w-30 HDEO? Dave

 

[nanney]

So what happens to the dino 10W30 above 86 degrees? And more importantly, what's happening to my engine when the temp is above that point and I'm running a regular 10W30?

 

[Roger3116]

I was thinking of running ESSO XD-3 0W40 all year round in my wife's 93 Exployer. I wonder if it is ok for the summer--it only get to the 80's once and awhile. If this oil is available where you are I have heard some very good things about it. What do the experts think? Roger

 

[TallPaul]

Good point Motorbike that Nanney's "engine appears in good condition still w/o need for an oil pressure guage and no real need to change brands or viscosity." On a similar note you said my analysis showed that I could run 10w30 Maxlife and to think about what my analysis taught me. Well maybe I need Dyson, but here is my understanding: Running a 5w30 (Durablend) when I put in the oil pressure gauge I noticed pressure was running 36 psi hot at 2000 rpm and 16 at idle. When I ran it hard the hot 2000 pressure would drop to 30. Spec for this engine is 40-60 at 2000, so I drained two qts and added two qts 20w50 for approximately a 10w40 (or maybe a thick 10w30) and pressure went up to around 44 psi. While the 30 weight was OK by the tough and dirty rule of 10 psi per 1000 rpm, I felt better having it within spec and the 10w40 raised the idle pressure 6 psi higher too. Now, the puzzle is why is the pressure on the low side with xw30? The UOA seems to say the engine is in great shape without excess clearances and the consumption is minor (possibly more related to heavy foot than engine condition), so why the low pressure? The only thing I can figure is what my neighbor (an engineer at Ford) told me: that it could be a weakened spring on the oil pump relief valve. So at this point, given the UOA, the weak spring theory seems more likely. Anyway, I figure I am in the spec range (got it down to 40 psi running 4th gear at 80 mph into a fierce head wind for about 10 miles one winter day), so xw40 weight probably not a problem and I'm figuing so long as it is summer I might as well run 15w40, since it will have less viscosity index improvers and thus would be a bit more robust for summer temps. Also, the 10w40 has a higher HTHS than the 10w30. The 15w40 should have even higher HTHS and that should be a good thing. And on that note, why not use the pressure gauge to select a higher viscosity grade that still falls within spec? Higher viscosity is not necessarily bad, right? I've only had the pressure gauge since last Sept and so I might be suprised at what happens when it gets consistently in the 90s (F). [ April 18, 2004, 12:12 AM: Message edited by: TallPaul ]

 

[Pitbull]

What's your owners manual call for? I bet it recommends 5w30 and or 10w30. If you want to change go with Mobil 1 10w30. The manufacture knows more about what oil viscosity to use in that engine then anyone on this site. Don't play games with your engine. Upgrade the oil quality don't change the viscosity.

 

[TallPaul]

quote:

---

Originally posted by Pitbull: What's your owners manual call for? I bet it recommends 5w30 and or 10w30. If you want to change go with Mobil 1 10w30. The manufacture knows more about what oil viscosity to use in that engine then anyone on this site. Don't play games with your engine. Upgrade the oil quality don't change the viscosity.

---

The owner's manual recommendationi is tainted by EPA requirements related to the manufacturer's ambition to reduce CAFE fines; however, mine does recommend 10w30 for anything above zero F. A former Ford engineer told me that by the time all the other folks at Ford get done revising the owner's manual you would hardly recognize what the engineers originally said. Also, the owner's manual may not anticipate an engine that has below factory specification oil pressure. Maybe the great UOA I just had was because of the 10w40, not in spite of it. If one were going to a thicker oil grade and had some doubts about the wisdom of such a move, then synthetic would be the safer bet for that higher grade.

 

[nanney]

It specs 5W30 on the oil cap and the manual says 5W30 or 10W30. The factory fill was 5w30, but the local toyota dealership uses 10w30, so I continued that route. By the way, still looking for a response as to what happens to dino 10W30 above 86 degrees or what happens to the engine above 86 degrees when there is 10W30 dino running.

 

[Motorbike]

quote:

---

Originally posted by nanney: By the way, still looking for a response as to what happens to dino 10W30 above 86 degrees or what happens to the engine above 86 degrees when there is 10W30 dino running.

---

Nothing per my oil analysis's in my engines but...that's where generic owners manual suggestions fall short . Different engine types and gearing affect the end result for example a Miata with 4.10 gears running 4500 rpm at 80mph vs a new Grand Marquis with a 4.6 and automatic loafing along at 1900 rpm near same MPH . Typically a dino will thin down at high temp if it has some miles on it thus the recommendation for heavier oils in some owners manuals . Hail to the PAO's because there is no need to go thicker with those guys in a engine because of the better film strength at temp . Different engines , different driving stresses the oil in different ways so one just has to find an oil that works for his engine and driving especially as the engine ages .This is often done through engine oil analysis In your case engine blowby or engine oil consumption does not seem to be a problem so I question the need for a heavier vi oil unless you change your driving or use . Towing heavy loads for long distance would be an example but even then if a heavier oil or more protection was needed there are many oils that will fill the bill instead of using a 15w-40 diesel engine oil . [ April 19, 2004, 09:20 AM: Message edited by: Motorbike ]