Is Mobil 1 0w-40 too thin?

[John9721]

This is a follow up post to a post I made earlier and mistakingly put in the PCMO section. I have a ‘19 GLI (2.0T MQB) with an E85 tune. Car is spec’d for 0w20, I typically run a 504 spec 0w30. Most over there suggested what I was thinking, jump to a 40w oil to combat fuel dilution with E85. My first thought was Mobil 1 Euro 0w40, cheap and easy to find at Walmart. However in research, I’m seeing that this specific oil is known to be on the thin side of a 40w, nearly a 30w (please correct me if needed)

With that in mind, should I look a different route? Maybe the 5w40 version, or a Castrol Euro 5w40? I’m not super versed on reading a VOA to notice exact differences but I’m learning!

 

[BMWTurboDzl]

Nothing wrong with Mobil 1 0w40.
5w40 FS Mobil 1 is sometimes hard to find.
You could always try Quaker State Euro 5w40 or Pennzoil (Shell) Euro 5w40.

Castrol 5w40 is also fine if on sale, but I would choose the 0w40 over it.

Do you actually have fuel dilution of 5% or more?

 

[Brian123]

This is a follow up post to a post I made earlier and mistakingly put in the PCMO section. I have a ‘19 GLI (2.0T MQB) with an E85 tune. Car is spec’d for 0w20, I typically run a 504 spec 0w30. Most over there suggested what I was thinking, jump to a 40w oil to combat fuel dilution with E85. My first thought was Mobil 1 Euro 0w40, cheap and easy to find at Walmart. However in research, I’m seeing that this specific oil is known to be on the thin side of a 40w, nearly a 30w (please correct me if needed)

With that in mind, should I look a different route? Maybe the 5w40 version, or a Castrol Euro 5w40? I’m not super versed on reading a VOA to notice exact differences but I’m learning!

What Oil Temperatures are you seeing?

 

[JavierH19]

There's not that much of a difference between off the shelf offerings though some stand out more than others Like Mobil 1 ESP and Mobil 1 0w-40 and castrol 0w-30/40. The 5w versions aren't necessarily better in terms of viscosity and shear resistance even though you'd imagine they're similar to the 0w version but with less VII which should deliver better performance. They usually use the higher winter rating as an opportunity to cheapen the base stock a bit but at the same time if it still meets oem approvals then it's still good to use.

 

[John9721]

What Oil Temperatures are you seeing?

At the absolute hottest 225. On average 208-214 I’d say

 

[dnewton3]

The only way to know if the current lube is too thin, indicating a thicker lube is needed, would be to take several used oil analysis and see how they compare/contrast to known standard ("normal") wear rates. Unless you have a baseline, you have no ability to understand what changes are or are not advisable.

NOTE: you can NOT compare the lubes to each other, unless you do a true statistical micro-analysis. You can only use small sample sets relative to known Stdev variation; macro data analysis.

 

[kschachn]

It's a 40-grade, regardless of Internet lore.

 

[RDY4WAR]

Mobil 1 0W-40 will work. It is formulated on the lighter side of a 40 grade and has been known to shear out of grade, but I wouldn't worry too much about that given the application. E85 will dilute the oil more. However, in terms of viscosity, if the engine regularly sees full operating temperature above 174°F, the ethanol will evaporate from the crankcase. The bigger impact will be on anti-wear performance as ethanol will neutralize ZDDP. You'll want to change the oil more often.

A narrower multi-grade doesn't always mean it shears less. For example, KRL testing shows more shear from Castrol Edge 5W-40 (-13.7%) than Mobil 1 FS 0W-40 (-10.4%).

If it was mine, I wouldn't bother with any common oil off the shelf. I'd be using HPL No VII Euro 5w30 with has practically no shear (-0.5%), a more robust DI pack, no VII to cause negative effects with ethanol, and in base oils that are naturally more oxidation resistant.

You could get a poodle or spaniel for a guard dog and wonder if he'll be good enough, or you could get a dobermann and never have to question it.

 

[scrllock]

Nothing wrong with that oil for e85, at least for mild street use (225F is nothing). The guy who helped build my motor has a 2018 GTI at 700+ whp on e85 running Mobil 1 0w40. Stock bearing clearances, and without the advantage of your faster-spinning oil pump. No abnormal bearing wear over several years of hard use.

Of course every car is different, you could have a tune running crummy old injectors wide-open causing tons of washdown. If used oil analysis shows very high fuel dilution, the answer is replacing your injectors (especially on a tuned car running ethanol!), not trying to band-aid it with thicker oil.

Castrol 5w40 is fine, but I would stick with Pennzoil Platinum Euro 5w40 or Mobil 1/Castrol 0w40 if available. I'd change it twice as frequently (2000-2500 miles instead of 5k) unless you have a used oil analysis trend to support longer. Mobil 1 0w40 is generally the cheapest option, which I'd prefer given the more frequent changes. You could always run a boutique and establish used oil analysis trends to see if one of the more expensive options is worth using over longer intervals, of course.

 

[Brian123]

At the absolute hottest 225. On average 208-214 I’d say

https://www.widman.biz/English/Calculators/Graph.html

I have a lot of fun with this Calculator; I am big on the 10 number at a certain temp, but you are fine with Mobil 1 0W-40. You put the 40C and 100C Numbers in and see what you get. I remember that Mobil 1 Delvac ESP 5W-40 was good up to 239 at my 10 number. You can plug in some 5W-40 oils that you are looking at.

The reason I play with the calculator is for my air-cooled lawnmower engine. I am using Mobil 1 ESP 5w30 in my car now and with my calculator readings, I could go up to 226F. My riding mower runs at about 230F.

 

[johnmyster]

Car was spec'd around a 0w-20. Car is tune-only, 225 F max oil temp. We're worried that a 40 weight (specifically, BITOG posterchild 0w-40 M1-FS) is "too thin" because it's at the lower end of the 40w range?

Just making sure I heard this right.

 

[JavierH19]

"is 40 grade to thin for a 20 grade spec'd engine" a true thickie philosopher, an enlightened high viscosity ponderer.

 

[fantastic]

Car was spec'd around a 0w-20. Car is tune-only, 225 F max oil temp. We're worried that a 40 weight (specifically, BITOG posterchild 0w-40 M1-FS) is "too thin" because it's at the lower end of the 40w range?

Just making sure I heard this right.

Yeah, seems silly since car is spec'd for 20. 40 will work wonderful for op moderate intervals.

 

[John9721]

Yeah, seems silly since car is spec'd for 20. 40 will work wonderful for op moderate intervals.

Hey, can’t blame a guy for playing it safe!

 

[scrllock]

Hey, can’t blame a guy for playing it safe!

The bearings used in your motor are the same spec going back to older EA888.3 spec'd for 5w40. Only difference is your oil pump has less teeth so it spins faster in order to handle 0w20 which was spec'd for CAFE. Absolutely no reason a 40 grade won't be fine.

 

[svenson]

5w40 FS M1 is sometimes hard to find.

i wonder why is this happening from such a good company. i thought only in europe this only is missing.its a good 5-40 for who ever likes 5-40s.

 

[buster]

Consider Mobil 1 0w40 to be more of a 0w30 but on the higher end of the 30 grade. In real service, Mobil 1 0w40 is a 0w30.

 

[oldhp]

Are you running "true" E85 fuel OR E85 out of the local gas station? Big difference in % ethanol.

 

[John9721]

Are you running "true" E85 fuel OR E85 out of the local gas station? Big difference in % ethanol.

Roughly 72-74%

 

[SC Maintenance]

i wonder why is this happening from such a good company. i thought only in europe this only is missing.its a good 5-40 for who ever likes 5-40s.

Easy enough to find online - even Wally's has it for $25. I suspect its low volume hence no one will give it the shelf space, especially since the 0W-40 can be used instead - duplicate offering from the retail perspective.