I’ll start by admitting that I’m an outlier. I live in a hot climate – Phoenix, AZ, where temperatures range from +30 to 115 degrees. I have a problem with the 0W-20 Acura recommended oil viscosity. It seems very thin for these temps. Visions of the red-hot turbo bearings while climbing the 6% grades just outside our metro area give me chills.

Accordingly, for my first oil change I bought a 5 quart jug of 20W-50 Mobil 1 synthetic at Walmart, took it to the dealer, who gladly put it and charged me only for a filter and pan plug gasket. My understanding is that this doesn’t violate the warranty since 0W-20 is only “recommended”.

Anyone see a problem with this?

 

Not if you don't intend on keeping the car very long.

 

If you look at the manual if your ambient temperature is between -20F and 100F then 0w-20 should be used. If your ambient temperatures exceed that I wouldn’t go more than 5w-30. Running 20W-50 might be running a risk of engine damage since Acura already designed the engine for a low viscosity oil to make it more fuel efficient.

 

^ Yeah, I'm of this opinion. These motors are designed for a specific range of oil weights and unless you're doing heavy duty work with it. Eg. You're towing a lot AND you're running in temperatures outside the norm. While 0W-20 is probably not enough in your really hot Phoenix climate I have visions of excessive engine wear (and higher fuel consumption) running something like 20W-50 which is really now used just for heavy duty (taking it to the track?) work. I'm no engineer so I can't say what's a healthy weight to run (I'd guess 10W-30 though).

 

Short answer, yes, I see a problem with that.

Moving form 0W-20 to 20W-50 is akin to moving from the sublime to the ridiculous. For summer use in your climate, I wouldn't go any heavier than 0W-30.

 

Much of the internal engine wear occurs immediately after cold starts, before the engine oil starts circulating properly. A heavier weight oil will delay that process, and that's not good for longevity. There may also be a risk of excessive oil pressure, which could blow seals or gaskets.

And as noted, it's likely that fuel economy will suffer with the heavier weight oil.

 

Exactly, that's why 0W-30 would be perfect for the 100° season.

 

Sure you live somewhere that the car experiences 110f but the engine experiences 212-240+ oil temps. I think honestly running the weight oil is not smart, and the engine is not designed to handle the thicker oil you are running, and ambient temp or not, your engine gets much hotter then the ambient temp, so that is not a huge factor. This will cause bearings to be starved and other parts that require a super thin oil when the engine is cold to be starved of lubrication. Also the engine is most likely designed with very tight tolerances to be used with 0W-20 that the thicker oil can not properly work itself in between.


The warranty specify it recommended 0W-20 and does say using fluids specified could void the warranty, id say your in a grey area, but really your call, I don’t think it’s smart, if anything run 5W-20 or maybe 5W-30. I think you went very extreme and will end up in the long run wearing your engine out much quicker.

Think of it this way, what’s the difference of your engine internal temp being 220F let’s say and the external temp being 115F, vs where I live where the engine would also be 220F with an external temp of let’s say 50F, nothing because the engines both get up to ~220F and maintain that temp using the coolant to do so. So in reality your probably just risking starving bearings in the turbo/engine and causing high amounts of wear when you start the engine up every time

 

I think it is not worth the risk, and should change back to the manufacturers recommendations.

 

USE THE OEM VISCOSITY. *NO ONE* is smarter than the Engineers that designed the darn thing, no aftermarket guy, NO dealer mechanic, no aftermarket Dealer gross margin generating additive seller. Certainly NOT you service advisor.

The science (tribology) of these machines is well known, bearings--engine internal surfaces, turbo shutdown heat-cooking, oil contribution to cooling etc. etc. Generally, gasoline engines just don't fail or wear out anymore from oil issues ---if you change oil OEM spec intervals, or add oil when needed (note many/most? Owners dont add oil but cars dont use much anymore either). Even the auto stop-start stuff is fine form a oil & lubrication perspective...just darn annoying.

Oils are so good now, as long it's made by a reputable blender AND THE OEM VISCOSITY (only a few companies actually "make" base oil and the additives...most are blenders, using a recipe).

The convenience/dollar store "bottom shelf pseudo-brand" bottles are NOT always reputable.
Pretty much all other real brands in *north america* are fine. Fakes are common overseas.

NOT talking about oil for classic cars, restored cars, track cars, racers, modified cars. Yep they might have different needs.

I'm an outlier too on only this topic, as well as "a dude on the internets said" --- Retired chemical engineer, and I personally spent a lot of time in the Lubricants divisions helping manufacture and sell industrial lubricants, HDMO and PCMO. Lots of time around base oil and additive companies too. Was an STLE member-certified. Google-fu if you care.

There is a lot of oil nervosa out there.
Caveat emptor. Or just waste money and time...

 

You can be the worlds most qualified oil or gas octane expert, then go on a car/truck/motor cycle forum and they still wont believe you,lol

 

 

Please tell me that you mistyped your post above??? 20W50 is INSANE and you need to drain that and put in what's recommended or look into 5W20 at most. You swung the pendulum WAY too far on your choice of oil.

 

It won't break the engine anytime soon but, like I said, probably not a problem if you don't plan on keeping the car very long. At least, not for you.

Time was, almost every car took 10W-40. I don't know why you would use 20W-50, unless you had an unused supply leftover from an old Studebaker.

 

Generally agree, but time was, almost every American car had a big honking V8 with piston ring clearances you could stick a thumbnail into. That's how the "tuners" of the day pulled like 100 "extra" hp out of a big block V8 just by "blueprinting it". ( Getting it machined to the design specifications ). And hence the full-service gas station attendant who checked your engine oil level every time you got the humongous gas tank filled with gasoline. Cuz it really did drop between gas fills.

( A little before my time but I spent enough time in the back seat of my Dad's Buick station wagon that I knew the drill. A little thing called a fuel embargo happened around the time I started driving, and that shook things up a bit ).

Anyway, the sludge those big ole sloppy V8s ran with has nothing to do with the requirements of our little modern high-revving tight-tolerance engines. AFAIK modern synthetic engine oils that maintain lubricity at low viscosity were nothing but a dream "back in the day".

 

Believe it or not, my 1979 Scirocco used 20W-50 as the factory recommended oil grade.

 

I had a Black 79 Scirocco S with a red and silver stripe and Recaro seats. Bought it used from a VW dealer in excellent condition for around $6500. LOVED that car and bought it when I was in college.

 

Yeah, great car, my Scirocco was my first new car, I still miss it after all these years.

 

I would stick with 0W-20. The 0W, or viscosity at ambient temp, is definitely appropriate at 30F - 115F and will provide the best protection due to its ability to get to engine parts as soon as possible. Thicker than that will result in more difficulty in the oil pump getting oil up to the top of the engine when starting it. I could see the logic in going with 0W-30 but keep in mind, the latter number is the viscosity at 100C or 212F. Assuming your cooling system is in good shape, your coolant should still maintain a temp of 220F at max, in which case, the 20 is still appropriate. Yes, there are hot spots, such as the cylinder head, that are definitely >212F but that's going to be the case in any climate. 115F may seem hot but to your cooling system, it's plenty cool enough to bring 220F coolant down in temperature when running though a radiator with fans running on max. I for some reason, your coolant routinely got to 250F or something like that, maybe 0W-30 would be a good idea. But if that's the case, you have a problem with the cooling system.

Any well engineered modern vehicle should have a cooling system with the capacity to deal with high temps. The exception might be when all the factors line up just right such as high temps, AC on, a high load (like towing) and going up a hill. In which case you might need to give the car a break when the temp gauge starts climbing

 

I agree. 0W20 oil is super thin. Most manufacturers only use 0W20 for better emissions and fuel economy. I think it would only make a difference if you're at a race track though. I don't think the oil temperature will get high enough on the streets to break down the 0W20 oil. 20W50 is pretty thick. I'm not sure if it will do any damage to your engine or not.
Pennzoil Platinum 10W30 actually has the highest burn point I believe. 10W30 is the thickest I would personally go. Maybe do 10W30 is the summer and something a little thinner in the winter? Good luck.

 

Interesting thoughts, but all opinion. No facts or data on the suitability of 0W-20 in a hot climate.

Here’s some data for your consideration. My wife’s 2018 Kia has a 1.6 liter turbo engine similar to ours. The Owners Manual contains an oil viscosity chart that shows bars of recommended viscosity over a range of temperatures. It shows 20W-50 oil good from 20° to 120°. The lowest viscosity recommended is 5W-30. (I’m trying to scan and post the chart, but having difficulties)

Are Acura engines that much different, in areas like bearing clearances, turbo cooling, etc, to warrant so much difference in viscosity vs Kia???

Perhaps some poster could dig out their manual on another make turbo car and see what viscosities are specified for hot weather.

I consider Acura’s 0W-20 position, like the need for the Auto Idle Stop system, to be motivated toward meeting Federal fuel economy requirements. This is a management decision, not engineers. Note that the Acura temperature chart, in a post above, does not show the existence of temps above 100°. Hot climate lubrication is beyond them!

On another subject, does anyone know if the turbo is cooled by circulating engine coolant?

 

@Rollinon ...all I will say is this...run the 20W50 at your own risk and hope that if anything happens, Acura will warrant your issue. Whenever you deviate from what a manufacturer recommends, you place yourself at risk. It may end up being just fine...but then again it may very well be "too thick" and if your oil pump prematurely goes out and they find a high viscosity oil in your vehicle, then don't be surprised if your warranty claim is rejected. We all take risks in life but what all are saying is that there are better options than 20W50 that would provide great protection and would lessen the risk. As they say on Shark Tank..."I'm Out!"

 

Well if you relook at the manual, the arrows do point outside the 100F range, so technically it can be used even if ambient temps exceed 100F.

If you want more information, maybe the Honda Accord 2.0T forums can help. I still think you should go with 0w-20. For hot climates like yours, I think the Mobil 1 EP is better because Mobil’s website states that EP is better than AFE for cooling turbos.

 

I’ll give your my new opinion. I say leave it in, because I wanna see how long it takes your engine to grenade or start to have compression issues from oil starvation 😂😂 also the arrows point showing it covers temps ranges past what is listed

but honestly if your worried i would just run 0W-30

 

This is turning into another one of those threads where someone asks an off-the-wall question, and then when the collective recommends again the OP's intended course of action, he (or she) tells us we have no idea what we're talking about and does as they originally planned.

@Rollinon, here are a few questions/comments for you:

• Do you really think you're smarter than the highly trained and extremely experienced Honda engineers? If so, knock yourself out and continue to run that glue you're running.
• If I'm not mistaken, oil grades of 0W-20, 5W-20, 0W-30, and 5W-30 are all recommended for your engine in your climate; stick with any of those and the engine will easily outlast the rest of the vehicle. Fact of life. With that in mind, why screw around with an oil many times thicker than what Honda recommends?
• As for engine construction differences between Honda and KIA, yes, significant differences in materials, tolerances, and oil flows.

 

I’ll take Scotty’s word, go to 4 minutes

 

SOS (Same old story). Opinion only, from folks who haven’t climbed a 6 % grade in 110+ weather. No data, no facts.

Let’s end this unless someone comes up with something substantial.

 

So pretty much this thread was to ask people opinions but then just tell everyone “your wrong, I’m right, your opinion is invalid”.

Your not driving a freaking semi, it’s a 2 ton car, the standard oil can easily handle 110+ ambient temperature going up a 8% grade, 8% is absolutely nothing to a car, a semi pulling a heavy load sure.

Honestly a mod should just close this thread, the OP has a skull thicker then the oil he is using.

 

It’s funny. The OP is going against manufacturer’s recommendations and asking if that’s okay and if it voids the warranty. I think the OP already knows the answers to his question but is just seeking validation that what he’s doing is right.

I mean, we provided directly what the manual states about it and yet, he wants to refute it.

On rare occasions, my area has 100 degree temps but I actually live in the mountains and the grades here are 10-15%, and the OP is worried about a measly 6%? Lol

 

Welcome to the board!

I think you are right in asking questions, turbo operates at very high temps, extra stress not required.

Ok, here is my data, 2008 base rdx, Ontario, Canada location

Background
Engine has a turbo bearing oil cooled under high pressure, and implicitly low volume oil flow in that section.
Engine coolant acts as a secondary cooling system for the turbo that also cools the exhaust manifold, and is still working passively once the engine is turned off.
Maximum turbo pressure just around 13.5 psi.
Premium gasoline required.
The oem intercooler had already been replaced with an aftermarket unit with noticeably higher cooling capacity.

Using obd2 + dashcommand + iphone I monitored the catalyst sensor readings. Saw them spike from around 1100F to over 1500F within seconds of going up a hill at BELOW HIGHWAY SPEEDS while also activating the turbo ( towing a small closed trailer, doing around 50mph, night time maybe under 70F air temperature).
Location was rolling highway hills between Toronto and Kingston, canadian shield bedrock area, so maybe below 600f ASL. (I did not measure the grade).

I considered prudent to lower the spikes and decided on 1300F limit, it required taking foot off gas slightly, sometimes shifting into a lower gear to get higher rpm. Once i did that the temp readings became stable no matter the length of the grade.

Similar readings in winter conditions were not significantly different, or my choice of 1300F limit prevented a difference from becoming visible.

*** There was NO VISIBLE COOLANT TEMPERATURE READING DIFFERENCE, before or after, mostly below 200F cruising.

I am sure the tight turbo bearing clearance is a major reason for Acura to mandate only HTO-06 oil for this engine, to prevent deposits therefore oil starvation in a critical part. In fact the only Acura vehicle with this oil requirement, at the time of discussion:

https://www.bobistheoilguy.com/forum..._K24_oil_specs

So based on encountered temperatures, I would also consider the flash point temperature rating, more so in your case with at least 30-40F higher air intake conditions, even though it has a different engine, turbo design, etc.

I like the gas to liquid oil concept so using PENNZOIL Synthetic oil.

For the HTO-06 they have so far a choice of one 0w20, and two 5w30 oils.

In absence of a published shear rating@temperature numbers from Shell (they would be ideal to make a more informed choice) I can only look at viscosity and flash point:

Rating viscosity@100, flashpoint name
0w20 8.4 204C platinum
5w30 9.8 207C platinum
5w30 10.3 224C ultra platinum

I tried 0w20 for one cold canadian winter, did not seem to make a difference in cold starting.
The engine sound was distinctly different, both idling and with rapid acceleration. It had the benefit of idling at close to 3-4db lower noise though.

The PUP 5w30 @224 can accomodate a 35F higher hotspot temperature compared with the lower PP 0w20 @204C, all other cosiderations aside.
I am sure that the higher ambient air by a similar difference wont raise the engine operating temperature anywhere near the same number, would just run the fans earlier, longer. Turbo&exhaust might be a different story.

I know that city police cruisers and separately certain cars designed for desert conditions add an external oil cooler circuit solely for the oil, and specify a lower temperature thermostat, both do not require changing the running oil grade.

Older cars with conventional oil, think pre2000, used to chart different grades for different seasons/ambiant temperatures, case in point BMW:

https://www.bimmerforums.com/forum/s...out-15w-40-Oil

With the improvements in synthetic oil, even the BMW manuals had a single recommendation grade for all temperatures:

https://www.bimmerforums.com/forum/s...an-NYC-climate

I expect that in practical terms, the higher viscosity will impact/decrease mileage. A back of the envelope estimate of say 1mpg difference or 0.5L/100km might cost extra at the pump, maybe around 5%. Every year could be the same amount or more as this 30 row 10AN covered fan oil cooler:

https://www.ebay.com/itm/30-Row-10AN...pid=3024256288

This also has the incremental benefit of MORE OIL AVAILABLE TO THE ENGINE.

In my case I can sometimes find the pennzoil platinum type at WM, the ultra is nonexistent here as far as I can tell, so not much of a choice.
I could also do the said cooler for the transmission and use the OEM for the engine oil if need be.

Ymmv, test, decide, let us know

Hope this helps

 

Altair, many thanks. Real data, at last.

I found Pennzoil Ultra Platinum at Walmart.com, also Amazon. Don't know if this works in Canada.

I'm on Mobil 1 because I've had good results with it in race cars. Don't know how to compare it with other brands. I am considering Castrol Edge 10W-40.

 

Thanks, may have to drive over the border one day.

If you gave me your car for free to run in your conditions I would not run anything other higher than 5w30, see below:
Search for castrol edge 10w40 msds information

https://msdspds.castrol.com

Viscosity is around 14cSt@100c. I did not like around -2 cSt, but I think I could live with less than +1 cSt difference.
Castrol is not low deposit hto-06, mobil 1 5w30 is.
Flashpoint is ever lower at >200C.

Mobil 1 5w30 has 6c flash point advantage over PUP.
https://www.mobil.com/English-CA/Pas...CAMobil-1-5W30
Has 3.1 shearing, unsure how Pennzoil stacks up there.

So why pennzoil and not mobil for me? Used oil analysis report, iron ppm per 1000 miles seems to be better for same distance, almost 10%, just over 2ppm/1000 miles for Pennzoil:

https://www.google.com/amp/s/jalopni...1797241527/amp

How long are YOU PLANNING TO KEEP this car?


Your environment is about 45F higher than my ... special circumstances.
Your engine compression is higher, max boost around 20 vs 13.5.

According to boost calculator
https://racingcalcs.com/turbo-boost-...er-calculator/
Using 45% efficiency for turbo and boost, I estimate that at maximum boost, you are potentially dealing with an extra 60F from the intake at 2.5 atm, likely more than 100F on the exhaust side, hmmm your turbo bearing channels are more at risk than mine:

am running low deposit oil HTO-06
in lower grade 10.x cSt@212F.
have an improved efficiency intercooler saving some 15F
Have bypassed the AT warmer portion of the radiator (dont do it if regularly idling/stop&go traffic), ie not transferring transmission heat load to engine...another maybe 10F advantage
running with ~65% coolant concentration which at summer temperatures adds an amazing extra 4C to the boiling point at 15psi pressure (extra margin error if ever needed).
(Also reduces the freezing point by maybe 5x more likely not relevant to you)

All things that you may choose to do or not, nothing earth shattering or "required", choices as I said.

Would be interesting to read about your choices and results.

Hth

 

Lol...I like how this conversation ends up being exactly the same as what others have said...

 

Well, now we have anecdotal data from a completely different engine that happens to be in a car with the same name as the one in question. And we have a very well reasoned educated guess about what might be appropriate for the 2019+ RDX, which seems strangely similar to the relatively "uneducated" guesses that preceeded it. So if nothing else, I will sleep better after I drive up a curvy Rocky Mountain pass in summer, pretending I'm Mario Andretti, using nothing other than the manufacturer recommended synthetic oil.

As an aside, the last time I drove up Mt Evans to 14,000 feet, I saw several camo-painted test mule cars making the climb. Same the last time I was in The Badlands, except the caravan of Porsche Panameras was all in black; I guess they figured no-one would be fooled by camo paint. So don't think the car manufacturers don't test their cars under extreme conditions. They do.

 

There is some truth in that virtually all car manufactures are under pressure to improve MPG, hence newer low viscosity oils were introduced to the market. There are some debates happening on why lower viscosity oils offer less protection to the engine. Its very possible that Honda/Toyota and other were pressured to use lower viscosity oils by environmental agencies and other industry norms. Its possible that savings 1-2% savings in MPG come at a cost of less protection to engine. I dont know if manufacture always has the best interest for the user, there are other corporate pressures they must deal with.. If you plan on changing oil viscosity, I would do it after warranty is over and also would bump it to 0w-30 or 5w-30, going beyond 30 seems questionable.

 

The debate you are missing is the one about whether 0W-20 offeres any less protection than a good 0W-30 or 5W-30. There is now a HUGE body of evidence built up over the last 20 years which shows xW-20 oils are quite robust and offer, if anything, superior protection to xW-30 oils. Yes, xW-20 oils are slightly thinner, but that is only part of the issue, the additive package put in the xW-20 oils is arguably superior to pretty much any of the heavier oils.

If you want more evidence, look no further than the UOA database over on BobIsTheOilGuy.com; there are literally thousands of UOAs posted which will allow you to see for yourself.

 

0w-20 been used in Honda engines over 20yrs? Really?? When was the first time Honda used 0w-20? UOA on bobistheoilguy is OK, but lets see when those engines on 0w-20 have 200k miles, lets hope they are just as solid. The debate is still on, its not settled, and I can see both sides of it. Some people just think that manufacture has your best interest all the times. The main drive to lower viscosity oil was driven by saving MPG and getting government credits and stuff. Sure they will say it offers the same protection to put you at ease, but I have normal skepticism for each side of the debate.

 

I think you misread my post, I never said 0W-20 has been used in Hondas for 20 years; what I said was "There is now a HUGE body of evidence built up over the last 20 years which shows xW-20 oils are quite robust..."; if I recall correctly, Honda didn't start recommending 0W-20 until something like the 2007 model year.

As for when Honda moved to the xW-20 grades, I believe the first year they recommended 5W-20 was either the 2000 or the 2001 model year (my 2001 Accord recommended 5W-20). Speaking of my Accord, the engine had just over 200,000 miles on it when I donated it, and even though I'd practiced 10,000 mile OCIs with 0W-20, it still did not use a full quart between oil changes. My TL is similar (albeit with only 160,000+ miles on it); it uses about a half quart of 0W-20 every 10,000 miles.

Regarding 0W-XX oils versus 5W-XX oils; the former is virtually always superior to the latter in literally every measurement metric. Said another way, if 5W-20 is good, 0W-20 is even better in literally every measure.

 

And when first gen RDX turbo came out in 2007, they set it to 5w-30, did they have concerns that xw-20 is not good for turbo at high temperatures? Did they succumb to tighter environmental to recommend xw-20 instead of xw-30 in next gens? All interesting questions. There are some people that say engines are so tight now that thicker viscosity xw-30 is no good. Do you really think using xw-30 instead of xw-20 will cause harm? I certainly do no want to find out in my car.
for the 0w, I agree, its better for cold engine startup in colder climates. Its also OK in normal climates, its a good idea for initial engine start when oil is cold

 

Wow, this thread was brought back from the dead. The only mass market 20W-50 synthetic I've seen is Valvoline VR1. M1's synthetics are 5W-50 or 15W-50, unless OP is using motorcycle oil. As far as 0W-20 having a better additive package ... maybe, but it varies depending on the manufacturer. I'd tend to agree seeing as the additives are likely needed to provide adequate protection seeing that the oil itself is quite thin, especially for higher temp climates. If you use the Euro Spec/Formula oils tho like Castrol 0W-30 Euro or M1 0W-40, their additive packages are likely as good or better (perhaps due to their extended drain intervals?). I'm all for using thicker viscosity oil, but a 50 weight oil is a bit excessive IMO for a 4-popper, even in AZ summers.