Diesel truck engine oil in your car?!? (or scooter)

Life Cars & Motorcycles
1

Ok, I’ve been researching oil on the web for awhile now. And from my days of reading…I believe that possibly the best oil to use in cars…or bikes (or scooters) is diesel truck oil.

The explanation is pretty simple. Diesel engines are much harder on oils than gasoline engines. Therefore the oils made for diesel engines are made to resist the increased pressures and frictions… Without increasing their thickness (you can get diesel oils in the same weights as regular oils).

You shouldn’t put regular oil in a diesel engine because it would break down the oil too quickly and it would lose its viscosity (slipperyness). But if you put the diesel engine oil in a regular engine the only thing it should do is last longer and protect better.

And to top it all off…diesel engine oil is cheaper… because the dealers buy it bulk since trucks can take as much as 18 liters at one time.

I’ve read university studies on the break down of oils in which they use machines that can measure the vicosity in oils…before and after long term use in a lab. I’ve also visited some motorcycle racing forums where they swear by it.

I put it in my CBR which had a noticeable ticking sound on cold start ups (which is fairly normal) and after switching to diesel truck oil…no more ticking during cold starts…at all. I even noticed the bike running cooler on the digital temp gauge…but that could have been my imagination.

I went to change the oil in my car today and I told the mechanic to use diesel truck oil. To which he thought I was :loco: . He then showed me a large container of the stuff that was 85 by 90 weight…much to thick to use in my car. But then I noticed another container near it that was 15/40 weight…and said on it “TURBO DIESEL” and below it said clearly “VW, VOLVO made in Germany”. I told him to put that in…and he phoned another mechanic to ask if he could…since he was afraid it would cause my engine to blow…and I’d sue him or something :laughing: . The other mechanic told him it was ok…so he reluctantly agreed in the end.

Their was another study done where they compared bike oils to car oils…and in general they found that the bike oils didn’t protect any better than the car oils…and the car oils are much cheaper on average. When they asked the oil companies why the bike oils were more expenisive, the companies said it had to do with “packaging”… since they sell less oils to bikes the bottle’s stickers…etc…cost more. But since they sell much more car oils…it lowers the cost.

Kind of like with eye drops…eye drops and saline solutions for contact lenses are the same thing…saline. One is a huge bottle that is cheap (lens solution)…and the other is a small bottle (eye drops) that costs more than the larger one. When they contacted the company to ask “Why?”, they said “Packaging costs”.

Anyway…getting off topic here. Point is I recommend Diesel Oil which meets and exceeds ALL standards set for gasoline engines (as well as diesel standards)…over regular oil which only meets the standards for one type of engine and not both.

2

that’s the beauty of an ancient engine design like the BMW boxer flat twin… Even though the engine managment is high tech, you can use old chip fat for oil and it’ll still run for half a million kilometers as long as you change it every 10,000km…

this diesel truck oil story sounds interesting though… I’ll begin web based research right away… got any links?..

3

Very good post Mordeth :bravo:

I have been using “car” oil in bikes for, damn, decades. Most guys I know been doing the same thing.
But this is the first mention I’ve heard of about diesel oil for bikes. I will pass your post on to some buddies for their …uh, digestion.
Thanks.

4

I’m at work now. I’ll get you the links when I get home…around 9:30ish.

Something else of interest…even though diesel engines have higher pressures and more friction…truckers of big trucks change their oils every…20,000 miles…either 20k or 50k…I forget which.

5

Here are some of the websites I used and some quotes from them:

“Three synthetics stand out from the rest: Mobil Delvac 1, Mobil-1 SUV and Shell Rotella T Synthetic. These are C certified industrial oils meant to be purchased in 55 gallon drums and used by companies which run a lot of diesel engines.”
motorcycleinfo.calsci.com/Oils1.html

“When asked why the Spectro 4 petroleum product sold for $5.00 a quart when comparable automotive oils could be found at less than $1.50…”
ducatimeccanica.com/oil.html

6

So? Have any of you been trying this oil? I’m about to start using Shell Rotella T in my motorcycle having also been steered towards it from internet research.

7

Very interesting stuff. I’ll be doing some reading on this later it seems. Mobil 1 I’ve always sworn by.

Subaru flat fours didn’t even need oil judging by the total lack of it they would often come in with. I love flat fours!

8

That Mark Lawrence article makes a pretty convincing case for the truck oils, but I wonder if you really need that much detergent in a bike. Diesels put a lot of soot in the oil, and IIRC someone pointed out in another thread that the more additives you have, the less oil you got.

Maybe the detergent would be useful in a motorcycle to keep bits of material from the wet clutch in suspension. A related point is to avoid oils with friction modifiers, since they can cause clutch slipping . I THINK neither of these points would apply to a scooter, or dry clutch machines like cars, and the BMW GS.

I wonder if the recommended viscosity ranges are unecessarily wide for Taiwanese conditions. With the short oil change intervals and low volumes involved in a motorcycle, reverting to a “traditional” winter/summer oil change regime might make sense.

They still seem to sell a lot of “straight” single viscosity oils here. Maybe they just havn’t caught up, but if you don’t need the low temperature performance of a multigrade, the better shear resistance of a straight oil might also make sense.

9

[quote=“Ducked”]That Mark Lawrence article makes a pretty convincing case for the truck oils, but I wonder if you really need that much detergent in a bike. Diesels put a lot of soot in the oil, and IIRC someone pointed out in another thread that the more additives you have, the less oil you got.

Maybe the detergent would be useful in a motorcycle to keep bits of material from the wet clutch in suspension. A related point is to avoid oils with friction modifiers, since they can cause clutch slipping . I think neither of these points would apply to a scooter, or dry clutch machines like cars, and the BMW GS.

I wonder if the recommended viscosity ranges are unecessarily wide for Taiwanese conditions. With the short oil change intervals and low volumes involved in a motorcycle, reverting to a “traditional” winter/summer oil change regime might make sense.

They still seem to sell a lot of “straight” single viscosity oils here. Maybe they just havn’t caught up, but if you don’t need the low temperature performance of a multigrade, the better shear resistance of a straight oil might also make sense.[/quote]
Good points Ed.

It’s generally good advice to go with the narrowest viscosity range you can get away with. A lot of people swear by single grade oil because as you say, the viscosity modifiers don’t lubricate the engine… the oil does. A lot of oldskool tuners stick to straight grade dino oil and would never use a multigrade or synthetic oil. I personally don’t mind multigrades but I do stick to those with narrower viscosity ranges like 15-W40 and will change grades winter / summer if necessary.

The effect of oil with friction modifiers on motorcycle clutches is also an issue, though it’s hit or miss whether your particular combination of clutch friction material and oil will cause slipping. I regularly run oil packaged for cars in my bikes because it’s so much cheaper, though I will search or ask for advice on that particular combo before doing so. Note that even when this problem occurs, as long as you switch to a more suitable oil quickly, no lasting damage is done to clutch. Switch oils and clutch friction is restored, so don’t let this factor scare you out of trying a car oil in your bike.

As to the use of diesel grade oils, many oils which meet the global diesel standard DHD-1 are marketed to both diesel and gasoline engines, so I don’t see that there would be any serious problem using them. Like Ed, I wonder if all the detergents are necessary and if their presence reduces the lubricity of the oil any. I don’t think I’d risk using it in a race motor but for the street I think it would be fine.

10

I looked for Shell Rotella T because it seems many guys use them from motocross to track day superbikes and day to day applications so. I think it is safe to say it has no clutch slippage issues? I found two varieties:

This one is either not synthetic or is a syn blend and hence its cheaper price, but it has a narrower range 15w40:

goods.ruten.com.tw/item/show?11080514779183

And this one is the fully synthetic one 5w40:

goods.ruten.com.tw/item/show?11090401113271

Which one would you say is better for extreme heat protection given Taiwan’s climate and the temps ones engine will reach in the city traffic?

Here is the Shell Rotella T website where you can see what the extra additives are:

shell.com/home/Framework?sit … _1006.html

With this pretty cool answer in the Faq:
"Do you recommend using ROTELLA in wet clutch applications?

ROTELLA T does not contain friction modifiers that are added to many passenger-car-only-oils, and it does not comply with all requirements of ILSAC GF-1, GF-2, GF-3 and GF-4 (the ILSAC oil specifications are often recommended by many gasoline passenger car engine manufacturers). That can be good for motorcycle/ATV use. Friction modifiers can upset wet clutch operation. And the ILSAC requirements limit phosphorus content.

Diesel engines and other engines with highly loaded valve trains, as well as transmissions, need extra (compared to passenger car engines) extreme pressure wear protection, which is provided by an additive that contains phosphorus.

One negative might be where the engine manufacturer recommends oil meeting JASO requirements. Part of the JASO requirement limits ash content to 1.2%.

Oil ash contributes to combustion chamber and spark plug deposits.

The ash content of CI-4 PLUS spec-ed ROTELLA T Synthetic SAE 5W-40 is 1.47%. However, the CJ-4 spec-ed Shell ROTELLA T with Triple Protection is now at 1.0% ash."

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[quote=“Dogma”]
Which one would you say is better for extreme heat protection given Taiwan’s climate and the temps ones engine will reach in the city traffic?[/quote]
If the blurb doesn’t say it’s semi-synthetic, then I would not imagine it is. No marketing type would ever pass up the mention. So, the 15w-40 is dino oil. 5w-40 has a much bigger viscosity range than you need in Taiwan, so I wouldn’t use that either.

And btw, I would not say that Taiwan’s climate is extreme when temps rarely climb above 35 degrees and never drop below zero except on the highest pass roads in winter. Rotella T is available in straight grades of 10w, 20, 30 and 40, though maybe not in Taiwan. I would consider a straight 30 for most of the year, and maybe a straight 40 for the height of summer.

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[quote=“redwagon”]
So, the 15w-40 is dino oil. 5w-40 has a much bigger viscosity range than you need in Taiwan, so I wouldn’t use that either.[/quote]

Eh either? You mean you won’t use dino oil and you wont use a wide range multigrade?

Whoa there, who said Taiwan’s climate is extreme? Not me! I said “extreme heat protection”

I said “extreme heat protection given Taiwan’s climate and the temps ones engine will reach in the city traffic?”

Which is a combination of factors that I have regularly encountered in Taipei when I’m sitting in city traffic on a windless 33 degree day and no shade with the only available air being the hot air rising from the blacktop and radiating from surrounding engines.

I would like to throw in the occasional track day too where the track seldom has any wind and the surface temps are very high and the engines are revving very hard out in the sun. The track is very short and speeds are hence very low.

So which would be the best to use with the combinations of all these conditions. Single grade? Multigrade? If so what ranges? Mineral or synthetic?

I would also like an oil that helps keep the engine temps down and cleans deposits it also needs to be cheap because I’m changing oil every 500km.

13

[quote=“Dogma”]
Eh either? You mean you won’t use dino oil and you wont use a wide range multigrade?
[/quote]Correct on both counts. Unless you are going to be operating at both extremes of the temperature scale on one fill of oil, then a wide-range multigrade is worthless. We’ve already discussed how the additives used to create this wide viscosity index compromise other functions of the oil.

[quote=“Dogma”]
Which is a combination of factors that I have regularly encountered in Taipei when I’m sitting in city traffic on a windless 33 degree day and no shade with the only available air being the hot air rising from the blacktop and radiating from surrounding engines.

I would like to throw in the occasional track day too where the track seldom has any wind and the surface temps are very high and the engines are revving very hard out in the sun. The track is very short and speeds are hence very low.

So which would be the best to use with the combinations of all these conditions. Single grade? Multigrade? If so what ranges? Mineral or synthetic?[/quote]
If I could buy a straight 30 weight synthetic for a reasonable price I’d do so. Since that’s unlikely I’d continue using a decent synthetic multigrade which is reasonable in price and widely available. I usually use Mobil1 in 15W-40.

Does your CPI have an oil cooler? I’d probably get one installed before I worried about using diesel engine oil vs. regular motor oil or where to find straight grade oil. That, and changing your oil more frequently, would I think protect your engine much more effectively. If you absolutely had to use either a diesel engine oil or a single grade oil, I’d go with a quality straight grade synthetic over a diesel engine multigrade whether dino or synthetic.

Hope this helps.

14

Yeah thanks for that. Oil cooler may be over the top, though, was just thinking about managing with what i have using lower cost high quality coolant and oil to manage the heat since the bike is already watercooled and purpose built for hotter climates.

I struggled to find Mobil 1 personally, I had heard its the dog’s jinglies but by the time I found it I heard they had changed the formulation and it was not the same anymore and had lost its allure it was the same article that led me to Rotella.

motorcycleinfo.calsci.com/Oils1.html

"Mobil-1 automotive oils all contain small amounts of moly - about 100 to 200 ppm. This can cause clutch slippage in some motorcycles. I’ve only heard of this being a problem in Honda Shadows. "

Also rather interestingly:

"I’m sometimes asked if it’s ok to blend your own oils. Yes, it is. Oils are all made out of pretty much the same chemicals, and nothing really bad will happen. If I wanted to blend my own oil, I expect I would use something like 25% Motul 5100 10W-40 and 75% Chevron Delo 15w-40, which would get me both the advantages of a lot of diester stock (5100 is pure diester) and the diesel additive package. In the winter, however, I would use 25% Motul and 75% Rotella synthetic, to get the superior low temperature performance. In fact, I just run Rotella synthetic in everything I own, year round: ST1300, DL650, Superhawk, Chevy Silverado, motorhome. "

Apparently diester is so effective at ensuring that there is no metal on metal contact that when you take the engine apart and try to clean it you need varnish remover to get the protective film off! Know anything about that?

May I sidetrack this thread into radiator coolants? Or is there already a thread for that? What is the best coolant to use in the radiator?

15

[quote=“Dogma”]
I struggled to find Mobil 1 personally, I had heard its the dog’s jinglies but by the time I found it I heard they had changed the formulation and it was not the same anymore and had lost its allure it was the same article that led me to Rotella.

motorcycleinfo.calsci.com/Oils1.html

"Mobil-1 automotive oils all contain small amounts of moly - about 100 to 200 ppm. This can cause clutch slippage in some motorcycles. I’ve only heard of this being a problem in Honda Shadows. "
[/quote]Yes, it’s a problem in some bikes and not in others. You can usually buy Mobil1 cheap in Carrefour or other big supermarket.

I have heard of this before. As I said before, I don’t think Taiwan’s climate varies enough to worry about it and again I’d say that keeping your oil cool would be more effective than any kind of homebrew lubricant you could concoct. Have you thought about sending your used oil for analysis? You’d have a much better idea of how often to change it in that case. 500km seems excessive to me.

[quote]
May I sidetrack this thread into radiator coolants? Or is there already a thread for that? What is the best coolant to use in the radiator?[/quote]
Please open a new thread for that. Thanks.

16

Thanks, if my engine temp light ever goes on then I’ll consider an oil cooler, at the moment I don’t have overheating problems, I just want to be nice to my bike so it lives longer and performs top notch.

In the meantime I think I would like to try 500ml motul with 1 litre Rotella T dino juice. Unless anyone sees any reason this could be catastrophic then this could be a good solution to getting best bang for my buck. I just hope the detergent function of the Rotella doesn’t cancel out the protective film from the Motul haha.

Really? The distance is too great? I need to change oil more often? :astonished:

You know someone local who can analyse my oil and say “hmmm, ok, you should change every xxxxkm’s” Sounds fun, got a phone number or email address?

17

For oil analysis, this is one way to do it…buy the Oil Analysis Kit and send your oil to the nearest test center (look at the list of centers on the right side of the webpage I have linked here), and wait for your results to come back…I haven’t trie dthis yet but it’s pretty straight forward and lots of people in America use this…hope this helps…

http://www.cropservices.sgs.com/oil-analysis-kit

18

[quote=“Captain Stag”]For oil analysis, this is one way to do it…buy the Oil Analysis Kit and send your oil to the nearest test center (look at the list of centers on the right side of the webpage I have linked here), and wait for your results to come back…I haven’t trie dthis yet but it’s pretty straight forward and lots of people in America use this…hope this helps…

http://www.cropservices.sgs.com/oil-analysis-kit[/quote]

Thanks for that Captain :slight_smile: , I had a look at a sample report, pretty much what I expected. It reports on the presence of foreign elements and metals from component wear as well as the additives in the oil, and from which of many components the source of the metals could be.

Unfortunately they do not come right out and say what my oil change intervals should be.

They do not in fact provide any advice for corrective action. I dare say the response to the question of “what should I do about my oil change intervals?” would be either it looks good keep doing what you are doing or hmmm looks a bit dirty change it more often. I very seriously doubt anyone will tell you to change your oil less often. :wink:

I imagine acting on this information would require some serious scholarly interpretation as to what is normal or abnormal for that particular motor at that particular stage in its life given the operating conditions during the time at which the sample was taken, and further diagnosis to eliminate one of no doubt many possible causes of the wear. Sounds like a Pandora’s box full of subjective argument waiting to happen. :ponder:

I think this would be much more useful for older machines that are not running right or where it is difficult to notice that they are not running right (oh that bloody old tractor has always been like that) or if you already kind of have a suspect but want to make sure before taking an important component of your means of production off-line…

For oil change intervals I think I would rather meet or precede the oil change intervals suggested by the manufacturer who has already gone through the bother of the research during the R&D cycle. As one guy said in post elsewhere “I really can’t understand the point of stretching your intervals to risk damaging really expensive components over the cost of a few bucks of fluids”

19

No, but other labs do. The idea is that you send them some of the oil you drained, they analyze it and give you a suggestion for a change period based on what they see. You should follow that advice and then analyze again to be sure.

Some other links for you:

blackstone-labs.com/do_i_need_a_tbn_.html
oil-analysis.org/tan_tbn_test.html

[quote=“Dogma”]
For oil change intervals I think I would rather meet or precede the oil change intervals suggested by the manufacturer who has already gone through the bother of the research during the R&D cycle. As one guy said in post elsewhere “I really can’t understand the point of stretching your intervals to risk damaging really expensive components over the cost of a few bucks of fluids”[/quote]
Note that the manufacturers do in fact have a vested interest in you changing oil more often than necessary. The truth is they make a lot more profit from doing service work and selling spares than they do selling new cars. The other point is that the manufacturer stands to lose big on warranty claims if they recommend an overly long oil change interval. The number they quote is of course a conservative number and could be extended in certain circumstances. Are you operating the vehicle in the way the manufacturer envisaged? Are you easier or harder on it than the builder planned for? Is the environment harsher or easier on it than envisaged? Even if you could discuss these things with them it wouldn’t be as effective as having an analysis done and actually knowing.

Personally I tend to stick to the recommended intervals unless I’m operating in very hot or dirty conditions, or running it really hard, in which case I knock 10 or 20% off the mileage before change. I don’t do track days with my vehicles, so I don’t have that calculation to make.

20

Thanks for that you guys have been very helpful :slight_smile:

My recommended intervals are 1000km, which I have dropped to 500km (given my usage is not just a track but an SM track which has dirt sections and I encounter alot of dust just practising turns and jumps on a pure dirt track which aside from the dust also drives my heat up) . Checking the Diesel oil out so that I can drop the cost of the more frequent changes and considering mixing in some high ester content for a margin of safety by strengthening the film. Dunno if me thinking is correct here. I am trying to find opinions on the consequences of this blend but it’s hard to come by. At my calculation I can drop my oil change cost by 50% or more even still blending in the most high end oils with the cheaper diesel oil.

The research so far is that the tests others are conducting on their oil is all pointing to the fact that the oil changes are not really necessary at the interval times, however all the advice is not to exceed your recommended intervals so as not to give the manufacturer any excuse during warranty period or even after should there be a recall or bulletin to lay any blame at your feet and deny you service.

I am also following another thread elsewhere where a guy is running a longevity test on Rotella T on a single cylinder 250cc off road bike to settle a debate regarding the usefulness and longevity of that product on a similar bike as mine is similar conditions.

I may do the oil test myself if his results show he needs more frequent changes since he rides alot harder than I do. But at the moment my CPI agent (who thankfully did study in the field at university) is aware of my activities and has himself recommended 500km oil changes so this will keep me covered from the manufacturer response side.

I am currently running Repsol 4T moto 15w-50 dino oil which my agent gave me, it is API SG rated which it seems is very hard to come by since that rating has been supplanted (don’t want to say surpassed because the greater consensus is that the SG rating was better) and it feels good but its NT450 a bottle and not even synthetic should I be concerned by the high viscosity? I did find that this oil is in fact recommended for large displacement high revving bikes which mine is not…

Incidentally in the user manual and across the whole back page CPI has a recommended oil called CPI Motosun, fully synthetic, API SL/CF 5w-50…