Best Gas & Diesel Oil????

[dnewton3]

I see the choice of oil vis as a preference, and not a "must do, must not do" situation.

I choose 10w-30 HDEO beuuase it can get down below zero deg F occasionally where I'm at, and will regularly get below +10. I like the quicker spin-up and oil pressure with the 10w-30. The 10w-30 is an approved (although not preferred) vis by GM for my Dmax. I have run 15w-40 dino and 10w-30 dino, and I like the 10w-30.

As for the 10w-30 consumption, I didn't find it all that much worse than 15w-40. Comparing two similar summer trips, one with each vis, I say perhaps a few tenths of a quart difference over an entire year! I generally consume around 2 qrts annually. In fact, because that represents the upper and lower portion of the range on the dipstick, I rarely even bother with a top off. I OCI in fall, when the heavy loads of summer RVing are over. I see zero consumption all winter. I only see consumption of oil after a heavy season on towing. One reason I don't add oil during my annual OCI is because when I do a UOA, I want to see how the initial host oil held up, with no help from a top-off. I don't see this whole 10w-30 versus 15w-40 debate reasonably teetering on the consumption issue; the difference is grossly exaggerated in most circumstances. After 7k miles (half of which are heavy towing for me) it might mean .2 or .3 of a quart differnce. Big whoop ...

And what of "consumption"? As long as it's reasonable (which I condsider mine to be) then it provides one an opportunity to replenish the oil and therefore the add pack. I never see "normal" consumption as a bad thing. Hence the term "normal".

My UOAs have consistently shown that my Dmax engine (all others as well) is really easy on oil, and do quite well regardless of brand or grade of oil used, AS LONG AS IT'S A PROPERLY QUALIFIED OIL TO THE OEM SPECS. That may or may not be true for the engines in the OPs quest.

We can be generalists here, and make some assumptions. And when people like the OP ask questions that are not well defined, we're stuck with offering answers that are somewhat generic. If he wanted to discuss heavy 80,000 pound OTRs, he probably would have brought it up.

For his applications, and desire to have one common oil, I see a 10w-30 HDEO as a great all-around performer, PRESUMING that it's a qualified and spec'd fluid for each vehicle. If not, then my suggestion is null and void. What is MOST important is how he values convenience versus specific application. Surely a 10w-30 will do well in all the vehicles he mentions. However, I'd be the first to agree that perhaps a 15w-40 for diesels and 5w-30 for the gassers would be more optimum for the engines, but only he can decide which is of more value to him, not us. 10w-30 will certainly work well, but it may not work "as well" as something more specific. This is exactly why I use 10w-30 in a lot of my equipment; commonization of fluids means less inventory and easier OCIs, etc.

BTW - when one runs the risk of "running out of oil due to increased consumption by using a lower viscosity...", it is not he fault of the lube. IT'S THE FAULT OF THE OPERATOR! It is completely unfair, and border-line silly, to blame a lube for a lack of proper maintenance. And maintaining fluid level is part of a proper maintenance plan. This is a pet-peeve of mine.

Want to know how to put this all to bed? UOAs, folks, UOAs. My suggestion is for 10w-30 all the way around. Try it. Even if it's not perfectly suited, it's not like the engines are going to self-destruct after one OCI ...

 

[daman]

I've only got around 900 miles on the T5 in the 6.5 and so far NO oil consumption,none what so ever.

some of that was towing my backhoe to a job site and other tools.

 

[Bambam]

dnewton sir, ye must have awfully nimble and well conditioned fingers with the amount of typing you do!

I must say a well worded and apprapo answer.

 

[daman]

Wonder what D's word per minute is? lol

 

[Gokhan]

In my case switching to 5W-30 tripled my oil consumption and resulted in tailpipe smoke when I drove off from an idling stop. I am more than happy with 15W-40, even though my combined MPG had risen from 27 to 29 with 5W-30.

I think I was also hearing more metal-grinding sound in the engine with the 5W-30, despite the engine being slightly more responsive. 15W-40 certainly gives me and added degree of confidence in engine protection no matter what the driving conditions are (except in very cold weather, which doesn't exist where I am).

Ultimately for me tripling oil consumption was an absolute deal breaker with 5W-30.

A Toyota TSB says (with respect to use of xW-20 in engines not certified for that viscosity grade), "DO NOT use these oils in engines other than those listed above. These low–viscosity oils cannot maintain lubrication effectiveness in engines with older designs and could result in smoke emissions from the tailpipe and/or unusual engine noise."

 

[Bambam]

You're basing this all on a TSB that has to do with a car that is 26 years old with over 200k on it??? Thats painting a picture with a rather broad brush sir. I applaud you for maintaining a vehicle that has withstood the tests of time and wear, but I find it hard to find a lesser vintaged Toyota running 15w40! Shame on me for not reading your signature,but it might have been wise of you to reference "your" particular situation, or are you still touting this philosophy for all cars?

 

[Gokhan]

Originally Posted By: Bambam
You're basing this all on a TSB that has to do with a car that is 26 years old with over 200k on it???

I gave the TSB as a reference for the newer cars.

As I said, using 5W-30 instead of 15W-40, tripled my oil consumption in my personal experience with my car, and this was an absolute deal breaker for me to use a thinner viscosity. (Note that my owner's manual recommends all grades between 10W-30 and 20W-50, and 5W-30 for very cold temperatures.) And, sure, there used to be days the oil consumption was imperceptible even with 10W-30.

I've never said that everyone should use 15W-40. You should normally use what is recommended in your owner's manual. If your manual recommends 10W-30 for your diesel engine under all conditions, absolutely go for it! But I personally wouldn't use a lower-than-recommended viscosity in any engine, for the reasons I will repeat one more time: increased oil consumption and increased tailpipe emissions (simple physics because thinner oil flows faster through small clearances), thinner oil film (again simple physics meaning less protection from contaminants that get into small clearances and also increased metal-to-metal contact, especially in older cars with larger clearances), smaller HTHS viscosity (meaning you can have less fun in high-temperature, high-speed driving), and lower pressure (which may increase engine wear at idle, where the oil pressure is already low).

 

[Bambam]

Wouldn't metal to metal contact mean there was no oil film between the surfaces whatsoever? If so,why? Is it the lubes fault? Or is there an issue of getting oil to the affected area?

Pressure does not equal lubrication, flow = lubrication.

How much jello(15w40) can you blow through a straw compared to water(5w30)? Takes more pressure to get the jello(15w40) through the straw than water(5w30) right? If I needed to get the most flow in a short amount of time through that straw, which one would I use?

How does a lower viscosity than spec'ed oil produce more emissions out the tailpipe?

 

[Gokhan]

Originally Posted By: Bambam
How much jello(15w40) can you blow through a straw compared to water(5w30)? Takes more pressure to get the jello(15w40) through the straw than water(5w30) right? If I needed to get the most flow in a short amount of time through that straw, which one would I use?

That's exactly why there is an optimum viscosity for a given engine. Too thick: poor lubrication because it cannot flow through small clearances, too thin: poor lubrication because of low film strength. That's why you should stick with the recommendation in your owner's manual, which is given according to what kind of clearances and pressures are present in your engine.

By the way, none of the common motor oil viscosities are jellolike in normal operating temperatures and they would all work virtually in any engine. This doesn't mean that you should use a thicker-than-recommended oil. But it's usually safer to use thicker-than-recommended than thinner-than-recommended because remember that all oils are thick when they are cold and your engine isn't damaged every morning, is it? Also, most owner's manuals will say "higher viscosities may be more suitable for high-temperature, high-speed driving."

Quote:
How does a lower viscosity than spec'ed oil produce more emissions out the tailpipe?

You have already answered this question yourself. Thinner oil flows faster, which means it will seep faster by piston rings and valve guides, leading to increased consumption and tailpipe emissions. It will also seep faster by worn seals, compounding the consumption problem.

 

[Bambam]

I don't have it in me anymore. I'm done after withthis thread after this post.

You have not proven anything stated with hard data, all I gather is;

1. you've read your owners manual

2. you perceived an issue with your engine when using a "lighter" oil

 

[Gokhan]

Originally Posted By: Bambam
you perceived an issue with your engine when using a "lighter" oil

Not perceived, firsthand experienced. There is a big difference.

For me experiencing tripling of oil consumption was an absolute dealbreaker for switching to a lower viscosity.

 

[dnewton3]

Your examples may be valid, if a bit dated.

Part of the point you make I might find some agreement with. In your Toyota example, they state to not use a vis that is not approved. OK - I can agree with that. There are many times when a thinner grade works perfectly well. Occasionally it does not work well. It's situationally dependent. A thinner oil in a 20 year old, 200k mile engine may not be a good idea. Your bearing clearances may be soo broad as to make the 15w-40 the only reasonable option. I will note, however, that if you hear ANY metal to metal sounds, regardless of lube, you're probably on borrowed time!

Furhter, you don't mention is, but I would like to simply mention that there is a difference between consumption and leaking. I'm not saying you have one or the other, I'm just noting it for the conversation.

As well, your consumption may be an issue of poor ring/wall fit. I had an issue with my older Vulcan v-6 due to an overheating event. I found my rings badly coked. After an ARX treatment, the rings were liberated and the compression (and ring sealing) were massively enhanced. Have you considered an ARX treatment or two to see if this "need heavy oil" issue can be resolved?

My comments were (in more than one post) predicated upon the use of APPROVED vis fluids. If a lighter grade is approved by the OEM, then there should be no fear in using it. Many OEMs provide ranges of fluid vis based upon envirnomental issues, OCI durations, etc.

IF the vehicles the OP has are rated for a 30 grade, then a 10w-30 HDEO will be a great all around, order-one-drum, kind of lube. If not, he's going to have to stock more than one lube vis.

 

[bullwinkle]

In defense of Gokhan-in an older, high mileage gasoline engine, especially one that has never had a rebuild or other major internal work-a higher viscosity oil isn't going to hurt anything, and will decrease consumption. My best example is my old 350 TBI Chevy Suburban-which in '94 was spec'd for 5W30, now gets either 20W50 or 15W40, and still has low hot oil pressure due to worn cam (& probably other) bearings @ 225K-ZERO blowby, cam & lifters still decent except for a little tick in extremely hot weather, no trouble starting down to +10F. BTW, my vote for the original poster is either Amsoil if you want to spend the extra money, or Mobil Delvac 1300 15W40-the only cheap multigrade dino oil I've heard that has the CF-2/Detroit Diesel 2-stroke (shear monster) spec!

 

[Trvlr500]

Speaking of oil consumption. As some here already know. I drive a car that is almost 40 years old. It's a '73 Cadillac Coupe. They were loose back then although the Caddy's were clearanced pretty tight. When they rebuild them they loosen them up for some reason.

I had the engine rebuilt about 95,000 miles ago and since it was new it has ALWAYS used oil. It'll go through a quart in 300 miles sometimes depending on how long it sits which in the past could have been 2 to 3 weeks.

Eventhough I have been driving it daily for the last three years and at time put some very high miles on it (1100 this week alone) it uses oil. About a quart every 500 to 1000 miles.

It runs so good and idles so smooth I really don't care but this IS a little ridiculous. I used Castrol 10-30 to break the engine in with back around 1997. Then went to Amsoil 10-40 for about 20,000 miles. The switched to Mobil 1 15-50 for roughly 10 years.

Since I moved to a MUCH colder locale I switched to Mobil 1 10-30 in the winter and the 15-50 in the summer. Then I tried PYB 5-30 due to the extremely cold temps where I was living at the time. Then to Valvoline VR-1 20-50 in the summer and then Valvoline 10-30 in the winter. I tried Mobil 1 TDT 5-40 for a while and am now using Rotella T 5-40. It seems to work fine down to -10.

I have always wonderd WHY this engine uses so much oil? Others that own this make and model of car ('73 Cadillac) don't use ANY oil! There has NEVER been ANY oil on the plugs in 95,000 miles. The PCV valve is always new or close to it. It doesn't leak or put out ANY smoke. White, black OR blue.

The only thing I can think of is that the guy's who rebuilt it were serious "motorheads". I think they "forgot" it was a street engine and set the piston to wall clearnace wider than it should have been.

As the manager of the shop told me one time. The ONLY reason street motors are clearanced so tight is for "longevity". With 95,000 hard miles on this thing it STILL idles very smooth and does'nt smoke. It runs like a new car when it's warmed up.

It makes no difference what weight, what brand or whether it is syn or dino it STILL uses at LEAST a qt every 1000 miles. I've had the intake off, the oil pan and the valve covers and the engine is like brand new inside. I can even see the tops of the pistons when I change the plugs. Tnere is VERY little carbon build up there. I can almost see clean metal in some places on the pistons.

The ONLY time it doesn't use any oil is on very long trips in the summer at 80+ mph for 2 or 3 hundred miles between fill-ups when it's running good and hot up around 220 to 230 degrees which is normal for this engine.

Any idea's?

 

[m37charlie]

For my engine,which is a modern Mercedes truck engine, MB says up to 0.5% fuel consumption is OK. I am very happy at 0.1%, or 1L/2200 miles.
Over a projected 28K OCI. I will get to renew my
oil with about 12.5L (29L sump).
73 Caddys aren't fuel misers, so your consumption may be normal.

Charlie

 

[Trvlr500]

Originally Posted By: Gokhan
Originally Posted By: daman
Experiment? what experiment?

it works no issues here...

did you answer Bambams question above yet?

Yes, I did, in my above post.

You might want to do UOAs with 5W-20 and 5W-30 and compare. Why are you using 5W-20 anyway? It's not worth the slight fuel-economy gain to risk increased engine wear by using an oil film too thin for your clearances.



Hi Gohkan,

I've been running thick oil for decades but it is because of the cars I drive. I love old cars and old V-8's. An old relic is cheaper to run, cheaper to repair, cheaper to insure, cheaper to register(taxes) and better for the environment regardless of the fuel mileage.

Maintinance on something so old is the problem when it is driven every day. I'll be buying a new, unsafe go-kart fairly soon, unfortunately and have to listen to "wheezing" and "squealing" instead of the rumbling sound of old time American torque and horsepower.

I've been driving a '73 Cadillac as my only car for 16 years. My past job allowed that. Things are different now even if I've been enjoying the "diesel like" torque of the only gas engine ever developed.

If you can believe it I'm down to Rotella 5-40 instead of my favorite 15-50 or better yet 20-50. I run it as thick as I can get away with depending on the temp which has beeen WELL down below zero where I have been living lately.

These newer cars are speced for "clipper oil" that I would never even consider putting in my Caddy but that is the way it is. Time marches on. When I DO buy a new go-kart I'll be running the clipper oil they recommend except I "might" go to a 5-30 insted of the 5-20 because of the way I drive.

5-20 is where it's headed. Unless you have the money for a REAL modern day Hot-Rod and even THEY are headed that way

If you can believe it, Ferrari and other makers of the "exotics" are actually wasting ink publishing the "C02" output of their super cars! It's quite hilarious. But politics rule these days.

Besides, anyone that can afford a supercar in this day and age can afford the engine rebuild and very rarely do they keep them long enough to find out what the clipper oil may have done to the engine at 8000 RPM.

When was the last time anyone heard of a Ferrari with 250,000 miles on it?

 

[Gokhan]

Originally Posted By: Trvlr500
I've been running thick oil for decades but it is because of the cars I drive. I love old cars and old V-8's. An old relic is cheaper to run, cheaper to repair, cheaper to insure, cheaper to register(taxes) and better for the environment regardless of the fuel mileage.

Hi Trvlr500,

I totally agree. I save roughly $500 a month over a new Corolla. I really hate the video-game-like steering in new Toyotas, where there is no road feel at all and it's even a pain to keep the car going straight in the new Corollas.

I did a lot of work on it recently and it's really a pleasure driving it -- almost like a sport car save the lack of horsepower and ability of super-tight cornering

. Fuel economy is also good -- with 15W-40, 26 - 27 MPG in mixed driving and ~ 35 MPG or more on highway. The only problem is the consumption of about 1 qt per 1000 miles in mixed driving but it seems to have not been increasing over the last few years; so, I am OK with it.

My decision to stick with 15W-40 came after the oil consumption went up to 2.5 qt / 1000 miles or more after trying 5W-30 for a thousand miles. So, for me to be able to use 5W-30 is not even too practical. I think for this car xW-30 is a borderline viscosity. The manual recommends 10W-30 at all temperatures but 5W-30 only if the ambient is below 50 F. For the diesel variant (honestly, it's a different engine [1C]), it's the same deal with 5W-30 but in this case 10W-30 is not recommended above 86 F ambient.

In response to DNewton3's comment, actually I don't hear any metal noise with 5W-30 but the engine sounds differently, as if the metal parts running closer to each other -- although it could be a perception issue.

I considered the Auto Rx suggestion by DNewton3 and others but in these Japanese-made Toyotas, the problem is usually some worn gasket or seal, or some failed emission device, not the precision-machined metal parts. I suspect an oozing head gasket causing the 1 qt / 1000 mile consumption. If I had a garage and the time, I would take it apart and replace all the gaskets and seals, but I don't have either and I am OK with this level of consumption. I did a carburetor rebuild a couple of years ago and that was fun. Also, CJ-4 HDEOs are really good cleaning oils, making the need for Auto Rx less than with other types of oils.

And I love the added degree of confidence of 15W-40 HDEO -- I would really be worrying for my engine if I was using xW-30 when I'm going 75 MPH uphill on 8% grade in 110 F weather when I drive to Las Vegas on I-15.

 

[vxcalais]

Originally Posted By: Bambam
Search AEHaas in the gasoline UOA section. He has been using thin oils in his exotic sports car for years. One car spec'ed a 10w60 and he is using 5w20. Now he doesn't have a long range or "lifetime" of data yet, but what he does have is proof that the thin oils will and are working just fine.

One article about a new to the market oil that happens to mention a claim you make is reason enough to believe it to be true and fact? I'd like to see some UOA's showing exactly what you said Gokhan.


I call the AEHAAS oil thing an experiment as well. He makes some points, but people use their daily drivers very different to performance exotic cars.

Anything that deviates from what is recommended by the specialist and manufacturers is what i consider an experiment. Those that use thinner are the ones that need to prove that it is not damaging the engine, especially low HTHS oils, unless the engine is designed for them. Its like computers, you overclock them to run faster, they run hotter, yes they work just fine, but everyone realizes they are reducing the life span of the processor. This goes with anything.

 

[Garak]

Originally Posted By: Gokhan
My decision to stick with 15W-40 came after the oil consumption went up to 2.5 qt / 1000 miles or more after trying 5W-30 for a thousand miles. So, for me to be able to use 5W-30 is not even too practical. I think for this car xW-30 is a borderline viscosity. The manual recommends 10W-30 at all temperatures but 5W-30 only if the ambient is below 50 F. For the diesel variant (honestly, it's a different engine [1C]), it's the same deal with 5W-30 but in this case 10W-30 is not recommended above 86 F ambient.


I don't necessarily agree with everything you've posted in this thread, but you have chosen your oil well, in my opinion, for your circumstances. I have no doubt 5w-20 is a great oil and has been back speced to a lot of vehicles; Ford has done this. However, as great as 5w-20 might be for where it's appropriate, it's not going into my old F-150, nor my Audi. If I had a new F-150, I'd use it without hesitation.

I wish I could go and grab any 5w-20 or 5w-30 off the shelf and use it year round. It would greatly simplify matters. That simply isn't the case for my applications or yours, for that matter.

 

[A_Harman]

Originally Posted By: jetman
Best Gas & Diesel Oil????

I'm gonna order a 30 gal drum of oil. I would like y'alls input on which type of oil would best suit our needs for BOTH our diesel & gasoline powered vehicles, if there is one? If not, then please make your recommendation for the diesels only.

WARNING: I PREFER AMSOIL PRODUCTS

We buy and sell 2 or 3 diesel pusher motor homes per yr. I want the option of doing XOCIs in the future. These coaches always have a pre-2007 Cummins 450hp M11 or pre-2007 500hp ISM engines with 10 gal sumps. I install an engine oil bypass filter system on them. They weigh < 45k Lbs, and get driven < 10k miles/yr. In the past, before I ever installed an engine oil bypass filter system, I've used Rotella T3 15-40w and changed it and the FF filter every 6k miles. I haven't done UOA on the diesels in the past, but I will in the future.

Our gasoline powered vehicles are daily drivers that get driven 18k miles/yr ea., a 07 Toyota 2wd FJ Cruiser 4.0L and a 08 GMC fwd Acadia 3.6L. I have installed TopDog V engine oil bypass filter(EaBP90) systems on each and run larger than stock full flow Amsoil or Mobil1 filters. They see rural easy 100% on road driving only. I do UOAs. I've been running Amsoil SSO 0-30w and doing oil and filter changes once/yr.

Thanks in advance!



You shouldn't be putting anything less than a 40-weight in the M11 Cummins. Those engines are designed for HTHS viscosities of no less than 3.7cP. Very few 30-weights have that kind of HTHS. Mixed-fleet oils such as RT6 or M1 TDT would be compromises that would be OK to run in your gasoline and diesel vehicles, but not perfect for any of them.