The two that had 30k intervals started using excessive amounts of oil right around 750k, of the other two, one made it to 950k and was just starting to use more oil than normal, the other one was overhauled at 900k and only needed it because a turbo failed and blew its guts into the engine, it was healthy otherwise
Okay, so everything else aside let me ask you this. If the owner of said trucks is overhauling both, what did he gain by changing oil twice as often on the ones that went 200k longer? Nothing, just spent more money and time changing oil. Likely 7k or so.
Now if he was running them and planning to get rid of them at 900k then yes he would've been money ahead changing sooner if that was the reason for the shorter life. There's usually a lot more to stories though. There's ISX that start drinking oil at 200k too. There's a lot of variables but in the guys case of 750 vs 950, if they are using oil, watching the oil condition and wear metals on a UOA for the longer drain versus shorter drain would show a trend. Sampling the 30k trucks at 15 would keep things consistent also for comparisons sake.
There's no way to say engine "x" can run x amount of hours/miles because there are far too many things that can effect the interval.
We don't run anywhere near new trucks, they seem to be fine with sensible long drains. The n14 in our feed truck I go 4x the factory interval (250hrs in 1996). We bought it with 720k on it and have put nearly 8,000hrs on it since then which would put it over a million miles if it was over the road. Wear metals are low, and oil consumption is still very low as well. But this doesn't mean anything because it's just one example and the next person will have a hundred different variables.
Of all of the stories of long drains allegedly being responsible for worn engines in here, how many of them were monitoring the oil with UOAs? There are a lot of people that run longer drains just because they are told to, this is really common with people that switch to synthetic. Running long drains without knowing what's going on is not a good idea. In many cases, things tend to go bad fast with oil, the potential for wear is not linear over time, it stays flat for quite awhile and then jumps exponentially. The exponential jump happens when the filtration is maxed out, or the TAN is close to or greater than the TBN. There are other things as well obviously but these two can be key. Filtration can be solved by changing the filter, but the TBN/TAN can't be fixed without new oil.
Long winded bastage.
Truth though.
The only scenario I have seen that contradicts this is a fleet that spun main bearings within about a month of one another. The combination of that one engine platform combined with extended oil changes has had a poor result, but with anything, there is always more to the story.
I have pulled down two engines in the last year running green (ethylene glycol? ) coolant with sca filtration. Neither showed any sign of cavitation. Nearly all of the tear downs running deac or elc have signs of erosion. Those two only had some scale.
Ethylene Glycol is the base for most engine coolants and has nothing to do with what the coolant type is. Propylene Glycol is also used for environmental reasons. When it is used the name usually has PG in it somewhere if it's an aftermarket brand. OE branded stuff (aka Bobcat Coolant) might not mention it.
Color means nothing but most green coolants are IAT (inorganic acid technology) which use large amounts of silicates and nitrites for protection. These are a couple of the SCAs that need to be tested for an added back into the system since they deplete rapidly. Not all IATs come pre charged with SCAs either. IAT coolants prevent corrosion and cavitation by forming a physical barrier on components, this protects well but causes issues in newer hotter running engines. Silicate dropout (gel) can also be an issue in things like EGR coolers. Conventional IATs can work just fine in most older engines provided the coolant is tested regularly and SCAs are added as needed either via liquid form or through use of a filter pre charged with them. The reason you see scaling is likely due to the phosphates in many of them combined with hard water. Most of the Extended life coolants are phosphate free.
The most common ELC coolants found in trucks are all OAT (Organic Acid Technology) either with (NOAT) or without (OAT NF) Nitrites. Color means nothing but of the main brands you see for trucks usually the NOATs are reddish and the OAT NFs are yellow which is not to be confused with HOAT (Hybrid Organic Acid Technology) "all makes and models" coolant which is also generally yellow. A big reason to not base things off color. OATs are Silicate and phosphate free among others. In simple terms they work by attacking the issue as needed versus just laying down a protective layer. The additives do not deplete rapidly like IATs. Most OATs are much more friendly to aluminum and high heat engines. Nitrite is still added to many because of its role in protecting against liner cavitation. However this is changing because the testing that has been done shows that OATs alone protect against liner cavitation as well, and nitrites do not always play well with aluminum at high temps. For this reason many new engines specify OAT NF. Nearly every engine from Europe requires it, Daimler, Volvo, Navistar, Iveco/Fiat, etc. OAT NFs are rated for slightly shorter intervals, 600k/6yr versus 750k/8yr is what some brands show.
This topic is the same as oil though. Every engine and situation will be different and without proper information (testing) you won't know what's going on. If you compare somebody running IAT and changing it every year to someone running an OAT for 5+ years and neither is monitoring anything then assuming the one with IAT will have less issues is plausible simply due to the frequency it's changed at, providing both are older motors that run fine with either.
You can't just run OAT forever, it needs to be tested and maintained just like IAT. IAT should be tested and then have the proper amount of additives added. Many don't do this but change their coolant filter with SCAs in it and end up doing okay. OAT should not receive these same additives, it does not do well with silicates. It will not blow up the engine or turn it to jello, but it's best to avoid it as possible. Most coolant manufacturers agree that up to 25% can be safely mixed provided the service interval is adjusted down. They would prefer you avoided it though.
On the topic of cavitation, not all engines will suffer from it even with the worst coolant maintenance while others can still have it even with the best. If cavitation is the only concern, proper testing and maintenance is more important than the type of coolant although the jury is still somewhat out on if nitrite free coolants are really almost as good as NOATs.
Some estimates I saw showed around 50% of mechanical engine downtime in the trucking industry was coolant related.
It comes back to the same thing as oil, just changing it a lot is going to give you better odds that you won't have an issue but actually testing things and knowing what is going on will be superior regardless of interval or coolant type, even more so with coolant than oil.
All I'm going to say is it's easy to tell who went to diesel tech school or works at a dealer shop.
Telling them they MAY save some money by doubling their service intervals because a mega fleet is doing it your probably going to be laughed at. I'm not saying your wrong, I'm sure it does work for some applications, and I like to gamble but I'll do mine in Vegas. At least there I get free cocktails and a good view.
I didn't go and don't work at a dealer.
You are correct that telling someone to double their intervals just because is wrong.
Who's the better gambler?
The guy that doesn't know what's going on, sits down at the table and places a bunch of bets or the guy counting cards paying attention to everything and knowing when to place a couple big bets. Bad analogy I know, but to me it's not gambling when you actually have an idea what is going on.
I went to a tech school and know many others that did across the nation and not a single one will agree that 50k oil changes are good. We have all seen what can happen from it. I have yet to find a tech school that doesn't push proper maintenance intervals. Same with factory training. I know on the cummins side of it , we teach what is right and not always what the sales men push to the customer. I get what your saying completely that to many people push the OK or it might work for a little bit type repairs. But to say tech schools and factory training pushes that is incorrect.
The factory OEMs list the long intervals including Cummins. I could pull them all up if you want. Many of the recommended intervals go as high as 50k or more depending on the conditions.
I'm not sure what salesman are pushing long drains but maybe that's the case. I don't talk to many of them or really listen to what they have to say, hard enough finding one that even knows what they are selling to begin with. The reasoning behind my choice to do so was based on my own research. Started with actually testing things and then extending drains if possible on non-warranty machines. I still have some "old-school" mentality and will change most things within a two year period or less even if everything is still good.
Volvo anything here in the states are not even quality boat anchors
Narrow minded much? Volvo builds some great stuff, just because the majority of their semis are cheap cookie cutter fleet trucks does not mean ever volvo product is bad. I can't say one bad thing about our loader other than the cost of Volvo parts, but I never have to buy any so it's not a big deal I guess. They are much advanced and efficient than others. I like my Cats too, have enough of their SSL's and been very happy, but their loader still hasn't caught up to the Volvo in the smaller sizes at least. The price does reflect that though. Just one example though, I'm not going to say everything volvo makes is the best because it's not, no company makes the best everything and even if they did, "the best" depends a lot on the situation.
Got my truck dropped off to the doctor yesterday, boss texted me today with the news........the head gasket is smoked, so at 1,020,000 miles its getting opened up for the first time, what was that about cat engines being piles of garbage?
I must have missed where that was said, cats are reliable in my mind just expensive to fix or rebuild compared to others.
