Mobil Delvac 15W-40 in my '24 GR86

[Al]

I have shifted to this oil bc of the higher I will lug the engine or even put a higher load on bearings when starting. It calls for 20wt. I changed that to 30 wt but after some thought went to the 40wt.

I originally was going to keep the vehicle 3 years but I love it so m uch I am going to keep it longer. I think I will 100% waste my mponey and to a UOA afer the oil is in 4000 miles. Just curious to see the composition of the oil.

 

[JavierH19]

Which delvac, the extreme version is real stout and yeah 4.1-4.2 hths is better than 3.5-3.7 of a 0/5w-40 if you're gonna lug it a little for the extra mpg. I know there was a guy on here that would lug his cobalt and got great mpg's.

 

[Patman]

I think there are a lot of way better oils you could have chosen for that instead of Delvac 15w40. I personally would have gone for something like ESP 5w30 or Pennzoil Euro L 5w30. I don't think you need an oil with a 4+ HTHS considering you're not taking it to the track. An oil with a 3.5 HTHS is just about perfect for spirited street driving, without making the engine feel sluggish or hurting the MPG too much. It just seems like way too big of a jump from a 0w20 to this choice.

 

[BMWTurboDzl]

I have shifted to this oil bc of the higher I will lug the engine or even put a higher load on bearings when starting. It calls for 20wt. I changed that to 30 wt but after some thought went to the 40wt.

I originally was going to keep the vehicle 3 years but I love it so m uch I am going to keep it longer. I think I will 100% waste my mponey and to a UOA afer the oil is in 4000 miles. Just curious to see the composition of the oil.

At $3.60/quart you'll have saved plenty of money to spend on gas.

 

[fdcg27]

A 30 grade I could see, maybe a Euro 40 grade, but a 15W-40 diesel oil?
Why?
Overkill (word, not the member)?

 

[Stumpy]

Delvac 1300 is a GREAT HDEO. Just look at the UOA's from my Scion and Mazda CX-9. I go 15K miles and the oil still has lots of life in it.

 

[Cujet]

300,000 miles down the road, it will still be running great.

 

[Dave Hess]

A 30 grade I could see, maybe a Euro 40 grade, but a 15W-40 diesel oil?
Why?
Overkill (word, not the member)?

10W30 is the grade I would use for summer driving and 7000 RPM shifts.

 

[TurboZedd-R]

Plenty of power dense 2.0s running on 0w20. The M139 and K20C1 run 0w20 without issue. Like other have said, a stout 30w will be just about perfect also.

 

[Al]

I do understand the logic of the 30 wt. I just feel that the way this vehicle is being (around town) the 15W-40 is the way to go. I could care less about mileage. I am not saying I don't get it up to 7K rpm a few times per week. I also shift at lower rpms whereby the next gear engages at around 2300 rpm. And yes I should keep it up to at least 2400 rpm

 

[Al]

300,000 miles down the road, it will still be running great.

Remember though Cujet this is a Subaru engine. Not as durable as Toyota engines

 

[VolkswagenFox21]

Subaru's Japanese site for a long time recommended 5w40 for the previous gen FRS/86/BRZ if driven spiritedly. I don't see why the 15w40 would cause any issues. I've been using euro 30w and 40w oils in my FRS for most of it's life and, of course, it's running just fine.

 

[SR5]

Lots of cars in Australia, of all types, running around on 15W40. Simply because all the majors make a 15W40 and sell them at a very low price point. You can get Castrol GTX, Shell Helix HX5, Valvoline Engine Armour and many others, all as 15W40 PCMOs. You can run them year round in our climate.

Mostly they were mineral oils rated API SN/CF and ACEA A3/B3, with natural low Noack and good shear stability. HTHS was around 4.0 - 4.1 cP, from the few that published this data.

More recently some have become semi-synthetic, e.g GTX UltraClean 15W40, and some like the Valvoline EngineArmour / DuraBlend have been upgraded to API SP, Euro ACEA A3/B4 and VW 502/505.

I was at a fuel station recently, and a guy in a nice suit and driving a new Audi bought some mineral 15W40, and I watched him pour it into his engine. He must have got a low oil light or something. Probably not the correct oil, but it will work just fine. At least he topped it up. A friend of mine has a Subaru WRX with the boost turned up, his mechanic told him to run a 15W40 HDEO, and that's all he uses.

I know it seems strange to the North American market, but over here, many people use 15W40 without concern. I often use it myself, and my oil stash contains GTX UltraClean 15W40 and Mobil Delvac 15W40 mixed fleet HDEO.

 

[Green Ninja]

I've been running 0w20 in my BRZ gen1. I drive it on the weekends and shift it above 6k a lot. I'm switching to 5w30 next OCI and getting the oil analyzed. thicker oil warms up faster tho, right

 

[Nessism1]

I don't see the point in running such a thick oil. The recommended oil is 0W-20, so if you want to step higher, 5W-30 is in order. 15W-40 is off the table. No reason what so ever to run oil that thick on a tight clearance modern engine designed for 0W-20.

 

[Al]

I don't see the point in running such a thick oil. The recommended oil is 0W-20, so if you want to step higher, 5W-30 is in order. 15W-40 is off the table. No reason what so ever to run oil that thick on a tight clearance modern engine designed for 0W-20.

Whell considering that this tight clearance engine can tun at a couple hundred cSts and much lower. How will a difference of 3 cSts have any effect..just saying. I drive this thing like a normal car. When the next gear engages I am at 2000 ish RPM

 

[Patman]

Whell considering that this tight clearance engine can tun at a couple hundred cSts and much lower. How will a difference of 3 cSts have any effect..just saying. I drive this thing like a normal car. When the next gear engages I am at 2000 ish RPM

It sounds like you really aren’t driving this car hard enough to necessitate a 15w40. You are just losing a little bit of horsepower and fuel economy. I still think you would be better off with one of the Euro 5w30s that has a 3.5 HTHS.

 

[ka9mnx]

Euro 5w-40

 

[SR5]

Euro 5w-40

A very good choice, especially when it carries Euro OEMs like MB 229.5 / .51 or Porsche A40. I'm just using GTX 15W40 because for me it's half the price of the Euro 5W40 synthetics.

Good 15W40 mineral Vs 5W40 synthetic talk here, with input from a guy who was an oil formulator.

Shell HX5 15w40 formulation

I already talked about this oil in other threads but i really ask myself how can pour point be so low (-45c) and flash point be so high (245c) for such a cheap oil? These are similar to the SHU 5w40 and even better than most euro grp III 5w40 available. Also it is SN rated and the newer batches...

bobistheoilguy.com

 

[si1491]

Plenty of power dense 2.0s running on 0w20. The M139 and K20C1 run 0w20 without issue. Like other have said, a stout 30w will be just about perfect also.

It is insane the M139 uses 0w-20 while my M133 (2015 GLA45) specs xW-40. I would love to see how long these engines last on the 20 viscosity, compared to the M133s.