Engine Oil Fuel Dilution Problem Is Back

[KWh]

Smaller displacement engines, which are the trend now due to ever tightening emissions, puts more demand on engine oil, not less.

I agree, don't see yet how this would ever apply to my 2.4 liter engine with a whopping 99kW.

The thing with this car is that the engine only puts out around 60-70 kW, which on that power gauge is about where the "V" in the word "PHEV" is. Which means that it revs up to max power nearly every time I get in the car and go somewhere on the freeway.

Also for the 2 litre engine this is a very low output, if it's built well (and it is), it should run for a very long time.

Revs are not neccesarily harmful (except for your ears :roll: ), an engine with high torq at low revs has a lot more to suffer

In a high performance European SUV, you won't use those upper rev ranges very often, because the ICE is sufficiently oversized

And still they don't come close to most of the Japanese cars in any reliability index. Despite the high revs of an average Toyota, Honda or Mitsubishi engine. By the way, the European brands usually have a 30.000km or two year oil change interval in Europe.

This is done because it's better to operate a smaller engine closer to its optimal point on the consumption map when you are cruising down the freeway than a larger engine at an inefficient spot because the power demands are too low BUT, it also means that when you do want extra power, you are stressing the engine close to its mechanical limits, and unlike in cars with a larger ICE, this happens routinely*.

Stressing an engine to it's max factory output is something completely different from stressing an engine to it's mechanical limit. Again, a well built 2.0 or 2.4 has a mechanical limit that's way beyond the maximum output of just 99kW. And according to the statistics, the Japanese tend to build their engines well.

There are a lot of high mileage PHEV's in the Netherlands and no reports of excessive engine wear what so ever. There are some premium European brands that could only wish for such a track record (just search for VW or Audi TFSI and Google will do the rest, these are by the way engines that perform very well in the lower rev range. They just consume more oil then fuel in the process, if the timing chain doesn't break first that is). For me this leads to the same conclusion as JaapV, absolutely no worries about the 20.000km service interval. Actually my first reaction was that this is a very short interval, beïng used to 30.000 :lol:

And no worries, you don't have to buy my car, I intend to drive it for a very long time

 

[ThudnBlundr]

OT - but commenting on an earlier post. Turbochargers have been common on diesel engines for decades. They will happily rev to 100,000 - 150,000rpm for years on their plain bearings as long as the oil supply doesn't become blocked. The trend for smaller, turbocharged petrol engines is purely down to fuel economy - you can use the engine closer to its most efficient map for more of the time. With a larger engine, you're often using it fairly inefficiently - look at how little power the PHEV often needs while cruising.

We had a Mazda5 7-seater with a turbocharged 1.6 diesel engine. It was fine if no road burner and returned a similar fuel consumption to the PHEV on a long journey: it returned far less around town. But when the pipe between the turbo and intercooler failed, it was literally gutless. It would barely climb a slight hill in first gear with my foot to the floor.

 

[littlescrote]

Due to these factors, it is highly doubtful engine oil technology has advanced enough where we went from every 3,000 miles, to 5,000, to 7,500, to now 12,000 or even 15,000 miles before engine oil change.

the oil doesn't have to change - the manufacturing tolerances and materials can improve to achieve that longer service interval. e.g. tighter piston ring and bore clearances will mean less fuel dilution of the oil in the first place.

 

[Woodman411]

Due to these factors, it is highly doubtful engine oil technology has advanced enough where we went from every 3,000 miles, to 5,000, to 7,500, to now 12,000 or even 15,000 miles before engine oil change.

the oil doesn't have to change - the manufacturing tolerances and materials can improve to achieve that longer service interval. e.g. tighter piston ring and bore clearances will mean less fuel dilution of the oil in the first place.

Fuel dilution is just one factor that breaks down engine oil: https://www.amsoil.com/newsstand/motor-oil/articles/why-motor-oil-deteriorates

 

[AndyH]

Something worth noting as we debate across the pond is that the quality of US engine oil is almost the worst in the world. The 3000 mile oil change idea is still king, and most oils are made just good enough to satisfy that. The folks at AMSOIL have been making long drain oils since 1972, and while the US didn't take the hint, Europe did - Euro oils and the many long-drain OEM specs have been pushing oil tech for a long time.

A few percent of fuel dilution might be a problem with a low-quality oil that starts off on the lower end of the viscosity range - if it's barely a 20W coming out of the bottle, and the anti-wear package is weak, 4% fuel dilution might make the oil a 0W-15 and it might not be up to the task. If the oil is 'thicker' out of the bottle, it might still be in grade with 10% dilution. TLDR: The fuel dilution number isn't the most important data point when predicting wear.

You don't have a problem as the Blackstone analyst reported: "...it doesn't look like it has caused any excess wear."

SAE 20 viscosity should be between 6.9 to <9.3 cSt at 100°C. You might submit a virgin sample to see if the oil is in grade out of the bottle.

Set the change interval on production of wear metal, TAN, and additive levels primarily. Total base number (TBN) isn't useful for gas/petrol engines. Run the oil until you see wear levels increase and change the next batch before the increase. (If you see AL and FE rise at 10,000 miles but they're ok at the 8K sample, change at 8K...)

Disclaimer...I was an AMSOIL DJ for about 12 years and worked with small gas and diesel fleet customers, setting change intervals based on oil analysis. I've been away from that work for about 10 years now so am likely rusty. YMMV, void where prohibited, objects in mirror are closer than they appear.

 

[ThudnBlundr]

Thanks for the expert input. However rusty, it's nice to have someone who actually knows what they're talking about :mrgreen:

 

[KWh]

Thanks for the explanation @AndyH
I didn't know the oil in the US is generally of such poor quality. It does explain why Mitsubishi sets the service intervals so short in the states.

 

[STS134]

Something worth noting as we debate across the pond is that the quality of US engine oil is almost the worst in the world. The 3000 mile oil change idea is still king, and most oils are made just good enough to satisfy that. The folks at AMSOIL have been making long drain oils since 1972, and while the US didn't take the hint, Europe did - Euro oils and the many long-drain OEM specs have been pushing oil tech for a long time.

Where would you put Mobil1 full synthetic on the spectrum of oil quality?

 

[AndyH]

Something worth noting as we debate across the pond is that the quality of US engine oil is almost the worst in the world. The 3000 mile oil change idea is still king, and most oils are made just good enough to satisfy that. The folks at AMSOIL have been making long drain oils since 1972, and while the US didn't take the hint, Europe did - Euro oils and the many long-drain OEM specs have been pushing oil tech for a long time.

Where would you put Mobil1 full synthetic on the spectrum of oil quality?

Sorry for the delay, STS134. I've been on the road the past 6 months. Happy to be home, but have some catching-up to do!

Oil quality depends on the application and the performance specs the oil's formulated to meet. Engine oil is formulated to meet performance specifications, and the way it performs depends on the engine its used in. Check the required performance spec for the engine and look for that on the bottle.

Going a bit deeper... In North America, marketers use "synthetic" or "full synthetic" as a marketing term. Unfortunately, here, it's misleading. Sorry...geek stuff follows... Engine oil is made from a base oil (about 70-75% by volume) and an additive package. The oil film keeps parts from touching most of the time. When the oil film breaks, the anti-wear additives provide a sacrificial coating. The additives control acid, control oxidation and nitration, contain the detergents and dispersants that control contamination from combustion and oil break-down, provide the anti-wear properties, etc.

The base oil can be made from any of the 5 major 'groups' or categories. Groups 1 and 2 are refined petroleum. Group 3 is highly refined petroleum that is also hydro-cracked and hydrogenated. The carbon chains in group 3 are more consistent than 1 and 2, but that's not saying much as refined petroleum is still a soup of heavy and light fractions. Group 4 is man-made synthetic - this is where we find polyalphaolephin (PAO). Group 5 is an 'all other' category. Petroleum jelly is here, but so are the synthetic esters.

In most of the world, if an oil is labeled 'synthetic', it's made from a combination of PAO and ester base oils, plus the additive package. In the US, thanks to a decision by the advertising division of the Better Business Bureau (I kid you not), Group 3 can also be called 'synthetic' in advertising. An example of how this works in the real world: After hurricane Katrina impaired oil refining on the Gulf of Mexico coast, Mobil couldn't get enough 'real synthetic' base oil. They changed the formula to include PAO, ester, and Group 3 base oil. It's a less expensive base oil blend that can still draw a premium price. It's their "tri-synthetic" product. Synthetic blends are made from petroleum (G1 or 2) and about 20% synthetic. In North America, that's normally a Group 2 and Group 3 blend that can't be called "synthetic" anything in the rest of the world.

If I used a Mobil 1 product, it would be their Extended Performance series. It's good for up to 15,000 miles or 6 months of severe duty. The 'severe' word is important. We're supposed to change the oil about twice as often in severe service, and most drivers are in the severe category. Most US products are built for a 6 month/7500 mile (or later 6 months/10,000 miles) of normal service. That's the main reason we hear the '3 months or 3000 miles, whichever comes first' quick-lube marketing message.

I hope that's useful!

 

[Woodman411]

Something worth noting as we debate across the pond is that the quality of US engine oil is almost the worst in the world. The 3000 mile oil change idea is still king, and most oils are made just good enough to satisfy that. The folks at AMSOIL have been making long drain oils since 1972, and while the US didn't take the hint, Europe did - Euro oils and the many long-drain OEM specs have been pushing oil tech for a long time.

Where would you put Mobil1 full synthetic on the spectrum of oil quality?

Sorry for the delay, STS134. I've been on the road the past 6 months. Happy to be home, but have some catching-up to do!

Oil quality depends on the application and the performance specs the oil's formulated to meet. Engine oil is formulated to meet performance specifications, and the way it performs depends on the engine its used in. Check the required performance spec for the engine and look for that on the bottle.

Going a bit deeper... In North America, marketers use "synthetic" or "full synthetic" as a marketing term. Unfortunately, here, it's misleading. Sorry...geek stuff follows... Engine oil is made from a base oil (about 70-75% by volume) and an additive package. The oil film keeps parts from touching most of the time. When the oil film breaks, the anti-wear additives provide a sacrificial coating. The additives control acid, control oxidation and nitration, contain the detergents and dispersants that control contamination from combustion and oil break-down, provide the anti-wear properties, etc.

The base oil can be made from any of the 5 major 'groups' or categories. Groups 1 and 2 are refined petroleum. Group 3 is highly refined petroleum that is also hydro-cracked and hydrogenated. The carbon chains in group 3 are more consistent than 1 and 2, but that's not saying much as refined petroleum is still a soup of heavy and light fractions. Group 4 is man-made synthetic - this is where we find polyalphaolephin (PAO). Group 5 is an 'all other' category. Petroleum jelly is here, but so are the synthetic esters.

In most of the world, if an oil is labeled 'synthetic', it's made from a combination of PAO and ester base oils, plus the additive package. In the US, thanks to a decision by the advertising division of the Better Business Bureau (I kid you not), Group 3 can also be called 'synthetic' in advertising. An example of how this works in the real world: After hurricane Katrina impaired oil refining on the Gulf of Mexico coast, Mobil couldn't get enough 'real synthetic' base oil. They changed the formula to include PAO, ester, and Group 3 base oil. It's a less expensive base oil blend that can still draw a premium price. It's their "tri-synthetic" product. Synthetic blends are made from petroleum (G1 or 2) and about 20% synthetic. In North America, that's normally a Group 2 and Group 3 blend that can't be called "synthetic" anything in the rest of the world.

If I used a Mobil 1 product, it would be their Extended Performance series. It's good for up to 15,000 miles or 6 months of severe duty. The 'severe' word is important. We're supposed to change the oil about twice as often in severe service, and most drivers are in the severe category. Most US products are built for a 6 month/7500 mile (or later 6 months/10,000 miles) of normal service. That's the main reason we hear the '3 months or 3000 miles, whichever comes first' quick-lube marketing message.

I hope that's useful!

Fwiw, in the BMW community, one of the most respected oil brands is Redline, which is a PAO synthetic (as are Elf/Total and LubroMoly, among others). I realize oil brands is a never-ending debate, and not to lose sight of the OP's point when everything is said and done, oil analysis is really the only way to validate your oil choice and your drain interval, regardless of brand

 

[jaapv]

Remains the fact that in Europe all car manufacturers advise oil change intervals between 10.000 and 20.000 km, nobody tests his oil, and despite this it must have been at least a decade since I last saw a blue-smoke exhaust on the road. Also, engine refurbishing businesses have all but disappeared.
Above all, I miss the burnt Castrol GTX smell... :lol:

 

[STS134]

Sorry for the delay, STS134. I've been on the road the past 6 months. Happy to be home, but have some catching-up to do!

Oil quality depends on the application and the performance specs the oil's formulated to meet. Engine oil is formulated to meet performance specifications, and the way it performs depends on the engine its used in. Check the required performance spec for the engine and look for that on the bottle.

Going a bit deeper... In North America, marketers use "synthetic" or "full synthetic" as a marketing term. Unfortunately, here, it's misleading. Sorry...geek stuff follows... Engine oil is made from a base oil (about 70-75% by volume) and an additive package. The oil film keeps parts from touching most of the time. When the oil film breaks, the anti-wear additives provide a sacrificial coating. The additives control acid, control oxidation and nitration, contain the detergents and dispersants that control contamination from combustion and oil break-down, provide the anti-wear properties, etc.

The base oil can be made from any of the 5 major 'groups' or categories. Groups 1 and 2 are refined petroleum. Group 3 is highly refined petroleum that is also hydro-cracked and hydrogenated. The carbon chains in group 3 are more consistent than 1 and 2, but that's not saying much as refined petroleum is still a soup of heavy and light fractions. Group 4 is man-made synthetic - this is where we find polyalphaolephin (PAO). Group 5 is an 'all other' category. Petroleum jelly is here, but so are the synthetic esters.

In most of the world, if an oil is labeled 'synthetic', it's made from a combination of PAO and ester base oils, plus the additive package. In the US, thanks to a decision by the advertising division of the Better Business Bureau (I kid you not), Group 3 can also be called 'synthetic' in advertising. An example of how this works in the real world: After hurricane Katrina impaired oil refining on the Gulf of Mexico coast, Mobil couldn't get enough 'real synthetic' base oil. They changed the formula to include PAO, ester, and Group 3 base oil. It's a less expensive base oil blend that can still draw a premium price. It's their "tri-synthetic" product. Synthetic blends are made from petroleum (G1 or 2) and about 20% synthetic. In North America, that's normally a Group 2 and Group 3 blend that can't be called "synthetic" anything in the rest of the world.

If I used a Mobil 1 product, it would be their Extended Performance series. It's good for up to 15,000 miles or 6 months of severe duty. The 'severe' word is important. We're supposed to change the oil about twice as often in severe service, and most drivers are in the severe category. Most US products are built for a 6 month/7500 mile (or later 6 months/10,000 miles) of normal service. That's the main reason we hear the '3 months or 3000 miles, whichever comes first' quick-lube marketing message.

I hope that's useful!

Huh. Okay so I've been using Mobil 1 (NOT Extended Performance). I'm running this current oil out to 7500 miles, then I'll send it in and report the results. I also have 2 more cases of Mobil 1 0W-20 to use up (12 quarts total).

After that, what do you recommend I use? Is there an oil that we can buy in the US that is exclusively Group 4?

 

[AndyH]

Sorry for the delay, STS134. I've been on the road the past 6 months. Happy to be home, but have some catching-up to do!

Oil quality depends on the application and the performance specs the oil's formulated to meet. Engine oil is formulated to meet performance specifications, and the way it performs depends on the engine its used in. Check the required performance spec for the engine and look for that on the bottle.

Going a bit deeper... In North America, marketers use "synthetic" or "full synthetic" as a marketing term. Unfortunately, here, it's misleading. Sorry...geek stuff follows... Engine oil is made from a base oil (about 70-75% by volume) and an additive package. The oil film keeps parts from touching most of the time. When the oil film breaks, the anti-wear additives provide a sacrificial coating. The additives control acid, control oxidation and nitration, contain the detergents and dispersants that control contamination from combustion and oil break-down, provide the anti-wear properties, etc.

The base oil can be made from any of the 5 major 'groups' or categories. Groups 1 and 2 are refined petroleum. Group 3 is highly refined petroleum that is also hydro-cracked and hydrogenated. The carbon chains in group 3 are more consistent than 1 and 2, but that's not saying much as refined petroleum is still a soup of heavy and light fractions. Group 4 is man-made synthetic - this is where we find polyalphaolephin (PAO). Group 5 is an 'all other' category. Petroleum jelly is here, but so are the synthetic esters.

In most of the world, if an oil is labeled 'synthetic', it's made from a combination of PAO and ester base oils, plus the additive package. In the US, thanks to a decision by the advertising division of the Better Business Bureau (I kid you not), Group 3 can also be called 'synthetic' in advertising. An example of how this works in the real world: After hurricane Katrina impaired oil refining on the Gulf of Mexico coast, Mobil couldn't get enough 'real synthetic' base oil. They changed the formula to include PAO, ester, and Group 3 base oil. It's a less expensive base oil blend that can still draw a premium price. It's their "tri-synthetic" product. Synthetic blends are made from petroleum (G1 or 2) and about 20% synthetic. In North America, that's normally a Group 2 and Group 3 blend that can't be called "synthetic" anything in the rest of the world.

If I used a Mobil 1 product, it would be their Extended Performance series. It's good for up to 15,000 miles or 6 months of severe duty. The 'severe' word is important. We're supposed to change the oil about twice as often in severe service, and most drivers are in the severe category. Most US products are built for a 6 month/7500 mile (or later 6 months/10,000 miles) of normal service. That's the main reason we hear the '3 months or 3000 miles, whichever comes first' quick-lube marketing message.

I hope that's useful!

Huh. Okay so I've been using Mobil 1 (NOT Extended Performance). I'm running this current oil out to 7500 miles, then I'll send it in and report the results. I also have 2 more cases of Mobil 1 0W-20 to use up (12 quarts total).

After that, what do you recommend I use? Is there an oil that we can buy in the US that is exclusively Group 4?

How long does it take you to hit 7500 miles? Short trips or a lot of highway miles? I ask because oil should be changed by mileage, time, or engine run hours whichever comes first, and highway driving is easier on engine oils than lots of short/local trips in very hot or very cold places.

I don't expect any company in the world makes an engine oil that's exclusively Group 4. PAO tends to shrink engine seals, and not all of the additive package components dissolve into it. Synthetic oils will use a bit of Group 5 esters (which tend to swell seals), and many additive packages will be mixed in a small amount of petroleum oil first before being blended into the base oil. In the US market, the only two companies I know for certain that use Group 4/5 synthetic bases are Redline and AMSOIL. Redline tends to be heavy in Esters, and their heritage is in racing where oil changes are VERY frequent. AMSOIL's main products are Group 4/5 and were built from the beginning to be long-drain oils.

The specifications are the really important part, though. As the additive package does most of the work, it's really important to start there. The base oil selected is more important for drain interval, though there's some codependency there. The manual for my 2018 says the minimum oil spec is ILSAC GF-5, with API SN as an alternate. ILSAC is a standards harmonization project between US and Japanese automakers, while the American Petroleum Institute (API) just focuses on US automakers. ILSAC GF-5 and API SN are functionally equivalent.

From the API:

Name Status Service
GF-5 Current Introduced in October 2010, designed to provide improved high temperature deposit protection for pistons and turbochargers, more stringent sludge control, improved fuel economy, enhanced emission control system compatibility, seal compatibility, and protection of engines operating on ethanol-containing fuels up to E85.

https://www.api.org/products-and-se...categories-and-classifications/oil-categories

Category Status Service
SN Current Introduced in October 2010, designed to provide improved high temperature deposit protection for pistons, more stringent sludge control, and seal compatibility. API SN with Resource Conserving matches ILSAC GF-5 by combining API SN performance with improved fuel economy, turbocharger protection, emission control system compatibility, and protection of engines operating on ethanol-containing fuels up to E85.

https://www.api.org/products-and-se...d-classifications/oil-categories#tab-gasoline

Lubrizol is one of two companies that designs and/or manufactures engine oil additive packages for I think *everyone* on the planet. This from their page on ILSAC GF-5:

Oils meeting ILSAC GF-5 are typically low HTHS (≤ 3.5cP) SAE 10W-30, 5W-30, 0W-30, 5W-20, 0W-20 and 0W-16 based on API Group II, Group III or Group IV base oils and coupled with API SN PLUS, API SN and resource conserving claim.

https://www.lubrizoladditives360.com/ilsac-gf-5/

You're using oil analysis and that allows you to develop a trend for the oil you're using. There's nothing wrong with Mobil 1, especially if you're not going to extend the oil change interval without oil analysis. I don't know the details of the metallurgy for our engines, so this is a generic look. Gaskets and seals in modern engines will leach silicon for a time when new. Si numbers will start high and decrease rapidly over the first year. The machines used to evaluate engine oil can't distinguish between silicon leaching from gaskets and sand/dust coming into the engine past the air filter. Si in the oil from gaskets won't cause wear. Monitor iron, aluminum, and lead for wear trends. If the oil film is breaking down and the anti-wear additive package is depleted, the camshaft will show wear first as cam lobes stress the oil film first. If the oil needs to be changed, either because the oil film is weakened by breakdown or fuel dilution, or because the anti-wear additives in the oil are depleted, you'll see iron and/or aluminum numbers jump up.

Looks like Mobil 1 has a new-to-me product (I've been out of this for about 10 years - not surprising! :lol: ) - their Annual Performance oil. They appear to recommend 'up to' a 1 year or 20,000 mile oil change interval for normal service. It has to be backed down to the OEM interval for severe service, however.

Follow your owner’s manual if the vehicle is operated in any of the following severe services: racing or commercial applications including taxis, limousines, etc.; frequent towing or hauling; extremely dusty or dirty conditions; or under excessive idling conditions.

https://mobiloil.com/en/article/warranties/limited-warranty/mobil-1-annual-protection-oil-warranty

It also looks like I need to edit my post above. Mobil 1's EP is 1 year or 15000 miles (whichever comes first) for normal service - this has to be reduced for severe service. It also looks like AMSOIL's added their OE oils (designed for regular OEM oil change intervals), and still have the XL series (up to 1 year or 12,000 miles of normal service). Their regular products are 1 year or 25,000 miles of normal service and 1 year or 15,000 miles of severe. All can be extended with oil analysis.

 

[STS134]

How long does it take you to hit 7500 miles? Short trips or a lot of highway miles? I ask because oil should be changed by mileage, time, or engine run hours whichever comes first, and highway driving is easier on engine oils than lots of short/local trips in very hot or very cold places.

Typically around 6 months. But of course, 7500 actual miles is probably only around 3000-4000 ICE miles. I try to keep the engine running for at least 10 minutes if it starts; if only going a short distance on the freeway (3-4 miles or less), I will generally try to keep it in EV mode.

 

[ThudnBlundr]

Remains the fact that in Europe all car manufacturers advise oil change intervals between 10.000 and 20.000 km, nobody tests his oil, and despite this it must have been at least a decade since I last saw a blue-smoke exhaust on the road. Also, engine refurbishing businesses have all but disappeared.
Above all, I miss the burnt Castrol GTX smell... :lol:

You should try driving a classic car I'm now putting in a more modern engine, but my '72 MG Midget used to leave a lovely blue haze in its wake until the engine was warm :roll: :lol:

 

[jaapv]

Maintenance required - my '63 TR4 doesn't

 

[ThudnBlundr]

It will

 

[jaapv]

It will

It is 40.000 km after an engine rebuild with new sleeves and pistons - no problems yet Simple yearly oil changes.

 

[Woodman411]

Huh. Okay so I've been using Mobil 1 (NOT Extended Performance). I'm running this current oil out to 7500 miles, then I'll send it in and report the results. I also have 2 more cases of Mobil 1 0W-20 to use up (12 quarts total).

After that, what do you recommend I use? Is there an oil that we can buy in the US that is exclusively Group 4?

Fwiw, here is a comparison video of the various synthetic motor oils, spoiler alert, Mobil 1 did not do so good. Amsoil, Redline, and Pennzoil ranked highest: https://m.youtube.com/watch?v=TWuKvnCq1js&t=1s