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Diesel Oil in gas motor?

toy4x4runner

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can you run 15W-40 "diesel" oil in a gas motor? Other than it keeping the engine squeaky clean will there be any issues? I'm running 10W-30 Mobil1 right now and am thinking about switching to Amsoil 15W-40 Diesel oil.
 
well I was at Amsoil's site and they "reccomend" 5W-30 Diesel oil for the powerstroke fords! I coudn't beleive it... 5W-30 oil in a turbo Diesel. I think my 10W-30 Syn Mobil 1 is better than running dino 15W-40. I'll stick with my 10W-30 syn.
 
our malibu ski boat (350 chevy, 2001), has a TON of hours on it (2500-3000), wasn't properly maintined, etc. THe dealer reccomends we run 15-40w oil now due to all teh wear on the motor already......
 
Wow, this is interesting, but i have said it before, and i'll say it again,,, i ran it once in an engine, because i got it for free, and well, it broke down extremely fast, to the point where it drained out like water, very black water, and wore out a camshaft and lifters in a motor that was rebuilt a year before this happened.

I have never attempted this again, and have never had any issues with wearing out cams or watery thin oil dropping out during oil changes.


JUST MY OPINION:D
 
I am confused. Deisel oil is designed for an engine that in itself was designed to typically go 300,000 miles before a rebuild, and this is usually not running to the store for milk, it's towing. So how could this oil be inferior or break down sooner? Oh, could that be why they hold GALLONS of it in their crank case? Yeah, I am just not seeing how deisel oil would be inferior to standard oil. If you look at the labels of Rotella it passes all the same clasifications that valvoline or whatever you choose does. But, on the other hand, wallyworld does sell a gallon on synthetic diesel oil for 14 bucks, so who knows. Anyone have any data on this?
 
is deisel oil alot thicker?
i wonder if it would better in the mini, the tranny is in the oil pan, and i have to run 20-50, because it acts as gear oil also
 
ok, i just read the back of one of the gallons of Rotella-T heavy duty oil we sell at the freightliner dealer I work at. Back says it meets or exceeds requirements. Something about ASI CI-4 standards? who knows. It also lists recommendations for using in gas and diesel cars and trucks. Typically the engines we work on don't get rebuilt unitll about 700,000 to 1 mil miles and above. Everything runs 15w-40 here. Who knows?
 
rotella synth is about 14 a gallon because a gallon = 4 quarts.= approx 4 a quart. mobil 1 sells in 5 quart bottles, for about 20, hence, you get the same, 4 dollars a quart. So really, from a price prospective, the synths are pretty close.

I will say rotella synth is pretty THIN when cold. hence its 5w40 rating, and not 15w40.

Given the choice, it depends. If you have a older engine, I think the 15w40 is ok. But if you have a newer one or a small motor (4 cylinder toyota or the ecotec) I would shy away, not because the oil is inferior, but that it would acutally rob mileage fromt he motor.
 
If the motor has had ****ty oil in it for its entire life then putting in an oil with a lot of detergents in it (diesel) will cause the ****ty oil's deposits to break loose. In those deposits is usually everything from dirt to carbon to old bearing material... which when released makes real good abrasive material... and tends to plug up things like rod bearing passageways and lifters.

A good place to look for deposits is on the high side of the head under a valve cover. It'll also be all over in the valley.

If you want to clean a motor out and let all that crap loose, dump a quarter of ATF in 15 minutes before you change the oil. I've gotten "floaters" out of motors with only 20,000 miles on them.
 
I know it's been mentioned before.I may be wrong on this seeing as how I'm not a lab tech and haven't done any scientific crap to base this upon, only what I've read about the subject. rotella 15w-40 (not synthetic!!!) has a large amount of zinc in it - which means that it acts as a more durable layer of lubrication between parts.
 
CyberSniper said:
If the motor has had ****ty oil in it for its entire life then putting in an oil with a lot of detergents in it (diesel) will cause the ****ty oil's deposits to break loose. In those deposits is usually everything from dirt to carbon to old bearing material... which when released makes real good abrasive material... and tends to plug up things like rod bearing passageways and lifters.

A good place to look for deposits is on the high side of the head under a valve cover. It'll also be all over in the valley.

If you want to clean a motor out and let all that crap loose, dump a quarter of ATF in 15 minutes before you change the oil. I've gotten "floaters" out of motors with only 20,000 miles on them.


Second that.

Kinda like putting valvoline in a motor that ran trop artic or penzoil. Say good bye to your lifters.
 
I run Rotella in 95% of what I own from the RV to the tow rig mud truck and my daily driver all v-8 chev, I have not had any trubbles with it yet but I have not run it in a motor that has run s**t oil in it.

My daily driver a 89 berb with a 5.7 has one cyl that uses oil not enough but enough to foul out a plug after 1000 mi tryed 10-30 and 20-50 still bad started running Rotella in it it uses less and have yet to foul out a plug in 3000 mi. It is also cheper then most good oils out there, last time i got some it was $6.79/gal

I have ran atf in a motor to help clean it out befor a oil change, one time drained the oil out then dumped a 50/50 mix atf and fuel oil let it sit and run for 20 min did this three times to clean most of the crap for running cheep oil, dumped 15-40 in it and it ran strong for another 35,000 mi till it was severly over heated and locked up from a stuck t-stat.

I rather run this then 20/50 these days
 
I have been running Valvoline Premium Blue 15w-40 in my K5's 350 now for 1.5 yrs. It doesn't see alot of miles but I have done at least 3 oil changes with it and it is fine IMO. I am going to continue to run it in my truck. If it is good enough to put in my Cummins then it is good enough for my K5.

Harley
 
ASI is some kind of institute thingy, CI stands for "Compresion Ignition" When you look at some castrol, it will say SI for "Spark Ignition"

I just wonder why this question keeps coming up. Don't think it's cheaper to do, and if you know regular SI rated oil has worked for 100+ years, why don't you stick with it instead of risking your motor's life? Just curious...
 
Again, my previous statement was just my opinion, maybe it was bad luck, bad timing, maybe the cam wasn't broke it correctly when it was rebuilt,,,,

I have never been able to duplicate the problem with that type of oil, but then again, i have never ran that type of oil in my gas motors ever since:D

as mentioned, if the stuff intended for gas motor use has worked and still does, why take any chances with the other stuff.

there has to be some diffenences with the oil, Diesel engines work alittle differently than gas, and are a "dirtier" engine, i know the big truck engines don't run at the same higher RPM's as car gas engines, they run much lower, 2000 RPM in my work truck engine is REALLY winding it out.

I dunno, just me personally, i won't/wouldn't use it, just stick with a good quality motor oil designed for your cars/trucks engine.
 
I run Delo-400 in my motorhome (cummins 5.9) and my Blazer (with over 150K on the engine and used 1 quart every 1500~2K miles) since I buy it by the 6 gallon case. It is excellent, premium oil and is qualified for gasoline engines however it is not an "Energy Conserving" rated oil. I run Mobil-1 10/30 in my LS1 because of the tighter bearing clearances. Many new cars and trucks only recommend 5/30 oil now. A friend of mine was having problems with Ford warranty because he was running a 20/50 and ford blamed the failure to lack of lube from too thick of oil.

I believe any 15/40 rated oil will be qualified for gas truck or Diesel
 
toy4x4runner said:
well I was at Amsoil's site and they "reccomend" 5W-30 Diesel oil for the powerstroke fords! I coudn't beleive it... 5W-30 oil in a turbo Diesel. I think my 10W-30 Syn Mobil 1 is better than running dino 15W-40. I'll stick with my 10W-30 syn.
Yes, 5W-30 in a Ford Powerstroke.... The main reason is that the injectors in the Navistar engines are hydraulically actuated. It's the HEUI system and Cat also uses it on some engines. the slightly thinner oil seems work a little better with this system.

I would trust Amsoil 5W-30 to protect my engine long before any dyno 15/40.

It's also great for cold climates.
 
toy4x4runner said:
can you run 15W-40 "diesel" oil in a gas motor? Other than it keeping the engine squeaky clean will there be any issues? I'm running 10W-30 Mobil1 right now and am thinking about switching to Amsoil 15W-40 Diesel oil.
Yes you can, I have ran 15W-40 diesel oil in multiple gas engines and it works just fine. The oil is just over kill, thats all.

Most diesel oils have additives that are designed to resist breaking down from soot and diesel, you don't really need that in a gas engine.

Let me know if you change your mind and want some Amsoil, I can give you a quote drop shipped to your door.
 
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