10W-30 OK over the summer?

[bird hunter]

Hey,

I ended up not driving my truck much over the winter and only have about 500 miles on the Rotella T5 10W-30 semi-syn that I use over the winter months. Is it OK to keep this oil in over the summer since I don't have many miles on it or should I change it out for 15W-40 that I normally run in the summer? Keep in mind this is Maine so we don't have too much hot weather and I don't tow or haul heavy. Thanks!

 

[icanfixall]

Thats not a problem to run that weight over the summer. If you have the oil specs for our engines the 30w30 is whats recommended year round mostly for the temps many of us see during the year.

 

[HS108]

Plus in Maine it's gonna be winter again before ya know it

 

[Kevin 007]

Yeah leave it in there. If you are to be towing heavy a lot or working it hard or something then that might be a different story, but otherwise it would be a shame to throw away oil that still has lots of life left.

 

[PwrSmoke]

Been running 10W30 Rotella or DELO in mine for decades. The only times it hasn't had 10W30 are in the days when the 10W30 diesel rated oil was unavailable in my area at various times. Straight 30 grade or 10W30 was the earliest recommendation before 15W40 took it's place in about 1986. I would second the caution that you might want to run a higher grade oil in particularly hot weather or rough towing duty but I can say that 10W30 didn't kill my engine towing at 18K GCWR across the country at various times in the '90s. And it's had a Banks turbo on it since almost day one. A few years back, I had 15W40 in it and hooked up my test oil pressure gauge and measured oil pressure at several rpms with the oil at about 170F. SHortly after, I changed the oil to 10W30 and checked again, making sure to measure at the same oil temps. I saw only about a 4-5 psi difference in oil pressure at 2000 rpm so I quit worrying.

On top of that, I found my engine runs a pretty low oil temp and think most others do too. I hooked up a temporary oil temp gauge (it replaced the dipstick) and found the oil only running 170-180F 95 percent of the time and never breaking 200F any time I had the gauge hooked up no matter how I worked it (to be fair, I'll disclose that I never did a 100 percent workout with the gauge hooked up either... maybe 75 percent at best). Since oil viscosity is a product of temperature, and since oil viscosity is rate at 212F, at any time you are running the oil below that rating temp, you are running thicker oil than you need. At 180, a 40 grade could be running in 60 grade territory and my 30 grade is well into 40 grade territory. If your oil temp never goes past 212F, there are only a few circumstances where you would need a 40 grade. A tired , well-worn engine might be one of them. I my case and in my operational scenario, I verified the 10W30 works fine.

The benefits? Much better cold starts and probably a slight bump in fuel economy. Maybe a little more power. The downsides only occur if you work the engine hard enough to get the oil really hot and keep it there long term. The diesel rated 10W30s are almost 40 grades anyway (very high viscosity in grade) so you get a lot of protection. The formulations (additive packs) are about the same in a family (e.g. Rotella or DELO), but the base oils are thicker in the heavier grades. The other downside to thinner oil is protection from fuel dilution. If you have a dribbler, slobberer, a short hopper or operate a lot in cold weather without taking some precautions, you could end up with a lot of fuel in the oil that could reduce the viscosity by dilution. That's not really an oil issue but one of care and maintenance but it could be a problem for some folks (a remote possibility since most diesel rated oils are deigned to deal with fuel dilution).

 

[chris142]

10w30 is fine but you may notice that your engine uses more of it than it did with 15w40..... mine drinks 5w40 like its free.

 

[FORDF250HDXLT]

i recently made the switch from 40w to 30w.i work my engine and i fear nothing.
if Navistar says it's ok to run 30w in temps up to 90F then it's good enough for me here in Maine.
i might do something else for July & August........but i doubt it.these are strong engines.i wont be loosing any sleep running 30w.

 

[idiabuse]

I use nothing but 10W30SAE30 AMSOIL so far Im at 10,000 plus miles with mine and no plan to change anytime soon.


Javier

 

[Kevin 007]

10w30 is fine but you may notice that your engine uses more of it than it did with 15w40..... mine drinks 5w40 like its free.

Strange. This might be due to the fact that the 5w-40 is synthetic more so then the viscosity

 

[chris142]

Ya that's a possibility.truck started good all winter with the 5w40 though. I went from a qt every 1500 to a gallon every 1000. I have been unable to find a sae30 with the proper diesel ratings here.

 

[idiabuse]

http://www.amsoil.com/shop/by-produ...hetic-sae-10w-30-sae-30-heavy-duty-motor-oil/

That is what I use, been very pleased with result's, my last 2800 miles used up 2 qts but I do have a small leak I have not sourced out yet.

I am sure this blend will meet your requierment's for the IDI engine.


Javier

 

[1466IH]

i buy the Case sae30 by the barrel an have been using it in my truck without any problems. it is what IH reccomends for all of their farm equip so i figured it would be good in the truck. i was told not to run rotella in these engines b/c for some reason it drinks it like water

 

[PwrSmoke]

When you get right down to it, any oil rated CF-4 or above and from straight 30 to 15W40 will be adequate in our engines if climatic conditions are matched to the viscosity and the oil change interval is adjusted to suit. "Optimal" is another discussion but a lot of that would have to match the individual situation (climate and operating conditions). I think strongly, and can show in many objective ways, that 10W30 is optimal for my truck in the way I use it today. That oil choice may not be optimal for another truck where and how it's used. Too often in these oil discussions people tend to ignore the details and want to proclaim one oil or one visocisty as "best for all." That's simply not true. You can make an argument over what's "best for most" and that's pretty much what IH and Ford did when they spec'ed the oils (or at least the viscosities... oil has improved so much since the '80s and early '90s) but no single oil is best for all. Applying the modern oil chemistries to older designs offers a lot more flexibility in viscosity choice (which can be an aid to fuel economy) and great improvements in cold starting performance and just about any other performance metric. The modern oils are so good that you can easily go past the point where the amount of money spent on the super-whizbang boutique oils is almost a waste in terms of what our engines need vs what those oils deliver.. looked at in the context of saving money, of course. My attitude is that if an oil can do 40% more than my engine needs, then that oil is costing me 40% more than I need to spend, so I adjust my oil choice down the rack a little. Heck, the average off-the shelf HDEO mineral or syn blend oils (Rotella, Delo, Valvoline, Castrol, Mystic, Motorcraft, even WalMart SuperTech or other house brand oils) are so much better than what our trucks were designed to use that it's staggering. Overall, it's just about impossible to make a bad choice if you buy a diesel rated oil.

 

[chris142]

When you get right down to it, any oil rated CF-4 or above and from straight 30 to 15W40 will be adequate in our engines .

Ya but all I can find is SM and SN gas engine oils and CF-2 diesel oil in sae30 around here.

 

[PwrSmoke]

And that is so bizzare. I'm out in Nowheresville, Ohio, and appear to have more oil choices than a dude in Caliprunia. where everything is normally possible.