Am i wasting perfectly good oil ?

[OM605]

I've always been a 3k miles oci believer since i started driving and for all my cars (mainly 90s Mercedes diesels and various other gassers from that era). I've used all types of xW40, dino, semi and syn. I'm educating myself here and decided to switch to 5k miles oci using either 10W40 semi or 5W40 syn. While it's still tempting to drain it early, i feel that with today's oil quality, the 15k kms (9k miles) oil change that the Mercedes dealer recommends for my car can become a reality. I feel like 5k miles is still a waste of money and ressources but at the same time you guys can convince me to have the guts to extend intervals even further. How far would go with these types of oil : - 10W40 semi, API SN, ACEA A3/B4, MB229.3 (such as Shell HX7) - 5W40 synthetic, API SN, ACEA A3/B4, MB229.5 (such as Total Quartz 9000) The car is well maintained, 95k miles, 70% highway, 25% country roads, 5% city, running E85.

 

[CT8]

Quality oil with the proper ratings is quality oil Spend some time looking at the oil analysis' and see how oils generally hold up. You seem to be getting long life from your vehicles

 

[Gebo]

I would stay at 5K max. Look at how well your cars are lasting. Seems you have been doing something right.

 

[Jimmy_Russells]

9k on synthetic with 70% highway is a walk in the park on gasoline. However, I wouldn't do it on E85. I would stick to 5k.

 

[ka9mnx]

Originally Posted by M119

While it's still tempting to drain it early, i feel that with today's oil quality, the 15k kms (9k miles) oil change that the Mercedes dealer recommends for my car can become a reality.

It has always been a reality with their recommended MB oil. Especially with your driving conditions.

 

[Silver]

Originally Posted by Jimmy_Russells

However, I wouldn't do it on E85. I would stick to 5k.

Ethanol shortens oil life?

 

[cristo]

My rule of thumb is every 5K miles on Turbo or otherwise high output high tech engines, and 7.5K for normally aspirated ones.

 

[Jimmy_Russells]

Originally Posted by Silver

Originally Posted by Jimmy_Russells

However, I wouldn't do it on E85. I would stick to 5k.

Ethanol shortens oil life?

85% ethanol does, yes.

 

[nascarnation]

Originally Posted by Jimmy_Russells

85% ethanol does, yes.

Does using E85 change the vehicle OLM life calculation?

 

[OM605]

Wow thank you guys for your help, so much answers ! As far as E85 some people say that oci must be shortened because of the extra fuel burnt while others say you can extend it because it burns way cleaner. Can't say, the oil looks identical. I've been using it exclusively for 3 years now in gas cars. The E250 diesel used to be the familly car and had 6/8k miles oci with either 15W40 dino or 10W40 semi. Not a single trace of sludge under the valve cover. Looks brand spanking new.

 

[ABN_CBT_ENGR]

Originally Posted by M119

While it's still tempting to drain it early, i feel that with today's oil quality, the 15k kms (9k miles) oil change that the Mercedes dealer recommends for my car can become a reality. I feel like 5k miles is still a waste of money and ressources but at the same time you guys can convince me to have the guts to extend intervals even further.

Let me give you the correct answer so you can make the best "risk based" and "business based" decision as fits your circumstances. This is the same question I get asked by every client I do a lubrication program for and the answer is universal whether its a gearbox at a mine in Grasberg or your car in your garage. Assuming you have a quality oil that meets the needs of your application...……. The oil will last (last being defined as serviceable for the application) until either the base oil and/or the additive package is depleted to the point that it no longer meets a requirement or contamination rises to the level where it can cause damage. That's it. That's he only correct definition of "bad" oil that needs changing. In an ICE there is no direct correlation between "miles" and oil life because there are too many variables. ( driving habits, fuel selection, engine wear, environmentals etc.)- even air filter choice. The only way to know is via oil sample and even then you have to have all the right tests done to get a full spectrum analysis as it pertains to your application. Once you have that then it needs to be trended in order to match with changing patterns and progressive wear of the vehicle because all that will have a direct affect on oil life. Then comes the value based decision ( where lubrication management ends and machine health begins)- how far toward end of life ( where a parameter is "acceptable" or "marginal" rather than optimum) do you want to go? This is where a slight trade off of "changing an older serviceable oil" with "newer serviceable oil" favoring higher asset protection over cost of oil versus taking an oil closer to "end of life" at the risk of a fraction of potential (not an absolute guarantee) of wear to the asset has to be made. Its not as much about guts as it is about making the informed choice with the proper supporting data in your personal vehicle maintenance plan and budget. If you think an extended change frequency is best for the wallet- you are right If you think a reduced change frequency is best for the vehicle- you are right The question is what's best for you in your overall plan?

 

[Jimmy_Russells]

Originally Posted by nascarnation

Originally Posted by Jimmy_Russells

85% ethanol does, yes.

Does using E85 change the vehicle OLM life calculation?

Only if it's a flex fuel vehicle designed to potentially use E85 from the factory. If it's an aftermarket tune or something (very common in the performance world) then no.

 

[DavidJones]

Nobody has a direct comparison to the way you drive and the your vehicle and it's use. You have to make yourself happy with your cars maintenance. I made the choice when I bought my wife's new Highlander Limited back in 2012 that it would get nothing but Mobil1EP in the correct weight on a 10,000 mile OCI. I even took the factory fill to 10K. As the car approaches 140,000 miles, it runs quietly and uses no oil. The percentages hwy, city, etc compare with what the OP listed. Gas used has been my wife's choice, since she drives it and she likes cheap, often stopping at Sam's on her way by. Engines and oils have come a long way and many people aren't taking advantage of that.

 

[OM605]

Thanks, the overall plan is to make the vehicle last for years, up to at least 300k miles. The thing is i don't want to put to much useless emphasis (and money) on oil while other parts of the car have to be serviced too, especially being old while i pile up miles and i'm very particular on things such as struts, tires, bushings and overall ride quality and confort.

 

[Jimmy_Russells]

Originally Posted by M119

Thanks, the overall plan is to make the vehicle last for years, up to at least 300k miles. The thing is i don't want to put to much useless emphasis (and money) on oil while other parts of the car have to be serviced too, especially being old while i pile up miles and i'm very particular on things such as struts, tires, bushings and overall ride quality and confort.

If it were my car I would do an oil analysis at 5k and go from there. If it's still ok then next time do 7k, and so on. You will spend a bit more now but then you will know a safe but also not wasteful OCI you can use for many years.

 

[OM605]

I think i won't be doing an UOA because it is not cheap to do one here, maybe 100€ and i'm not willing to put that much money especially if i have to do it multiple times.

 

[JMJNet]

I am surprised that people have not mentioned OIL ANALYSIS yet? to determine whether an extended OCI can be done.

 

[jurko]

Originally Posted by Jimmy_Russells

Originally Posted by Silver

Originally Posted by Jimmy_Russells

However, I wouldn't do it on E85. I would stick to 5k.

Ethanol shortens oil life?

85% ethanol does, yes.

Here's excerpt from The Royal Society of Chemistry on ethanol effects in engine oil. Mostly, it has been observed that the use of ethanol with fossil fuel can cause a significant effect on automotive lubricant's properties such a drop in engine oil viscosity, and total base number (TBN), as well as an increase in total acid number (TAN), and an effect on oil performance such as an increase in friction, wear losses and deposit formation resulting from oxidation and corrosion of bioethanol. The addition of bioethanol to gasoline enhances the tendency of the fuel to reach the crankcase of engine oil due to its higher heat of vaporization, thus increasing the rate of fuel dilution.11,29 Significant amounts of diluted ethanol fuel, in particular, E85 (between 6% and 25%) have been found in the engine oil crankcase after field tests12 and bench sequence tests.11,30 A study of fuel dilution was done by T. Hu et al.31 They explained that turbocharged gasoline direct-injection (TGDI) engine operated at high torque had a significant influence on fuel dilution (gasoline) which was found to be up to 9%. This percentage caused a decrease in oil viscosity, an increase in fuel consumption and the formation of carbon on the piston ring area.

 

[Jimmy_Russells]

Originally Posted by M119

I think i won't be doing an UOA because it is not cheap to do one here, maybe 100€ and i'm not willing to put that much money especially if i have to do it multiple times.

If you wish to continue using E85 I would stick to 5k in this case.

 

[OM605]

Very interesting js1956. From what i gather, 5/6K seems to be what i should stick to. I don't think i'm switching back to gasoline anytime soon as it costs two to three times more than E85. More and more cars are converted with a flexfuel kit in France as we speak (just like mine). Out of three gas stations, at least one has E85 now. Three yeas ago, there wasn't a single station selling E85 in my area and nobody knew what it was. A tank of E85 costs me 35€ while a tank of gas costs me 80 or 90€.