5W-20 or 5W-30 Motor Oil???

J

JaCkaL829

it was my first time...
As my title states, I'm having a hard time deciding which motor oil grade to use for my 2002 Acura RSX(base). According to my owner's manual as well as the oil cap Acura says to use 5W-20. I have been reading though that people on CRSX with base RSXs have been using 5W-30 with no problems. I have also read on there as well as other places that 5W-20 isn't the best motor oil for a car because it is thinner and doesn't protect as well as 5W-30. The main reason why car manufacturers are using 5W-20 is to boost MPG ratings on the EPA.



I really wouldn't mind using the 5W-30 if my car weren't covered by a warranty. I still have another 2 years on it, and would really hate to void it because I used 5W-30 instead of 5W-20. I do plan on switching to Mobil 1, after reading about Amsoil oils, but I'm still unsure of the grade for the reasons I listed above. I obviously plan on keeping the car for more than 2 years, so would want the best protection for the car. I also don't know the previous history of the car, it probably was serviced with dino oil, seeing how synthetic wasn't required for it and it was a lease. My car is about 3.5 years old and has around 43,xxx miles on it. My biggest worry is breaking seals, resulting in me burning a ton of oil, as its a reoccuring problem I've read with RSXs. If in the event I made the synthetic switch, and had problems with oil burning and took it to be serviced, I'm sure they would declare it was my fault for using the wrong oil grade (5W-30).



So right now I'm totally :nixweiss over what to do. I'm not sure if I should switch to synthetic or stick with the dino, and what grade to use. Any information/advice from the oil gurus would be much appreciated. If I don't get as much of a response I can always join BITOG and post like a total n00b over there, but I figured I ask Autopians on how they feel on the issue first.



Thanks in Advance :bigups
 
Stick with 5W-20 until you are out of warranty coverage, then whatever you choose after that. I doubt the 5w-20 will hurt much anyway. I've been running it since day 1 in my vehicle.



And :down to BITOG.. great way to shatter your self confidence and not know what to do! :(
 
the thinner oils are needed to meet emissions requirements. I'd follow the guidelines listed in the Owner's Manual. Honda has rigid guidelines for engine lube and it greatly exceeds API and ILSAC standards.





In an effort to control emissions, the top-most piston ring has been moved upwards. Heavier oils can't flow to these areas quick enough and oxidation, due to lack of cooling, is a common result. The engine designers know what they're doing :xyxthumbs
 
Use the 5W-20. There is no reason to go to the 30. In my Civics I always ran Mobil 1 Synthetic which I really like but the brand and type is all user preference.
 
Well, we can argue this six ways from Sunday, but so what if it's called out for fuel economy? If you believe the Honda engineers know what they are doing (which you did, otherwise you wouldn't have bought an Acura), then they knew what they were doing when they put 5W-20 in the manual and on the fill cap. Use what they recommend.
 
Setec Astronomy said:
Well, we can argue this six ways from Sunday, but so what if it's called out for fuel economy? If you believe the Honda engineers know what they are doing (which you did, otherwise you wouldn't have bought an Acura), then they knew what they were doing when they put 5W-20 in the manual and on the fill cap. Use what they recommend.
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Exactly. Plus, I am not 100% on the working of Vtec but I am pretty sure it is engaged from oil pressure so who knows how different oil weight might effect that.
 
I would stick with the recommended viscosity for all of the reasons already mentioned above.



I have also read it is better to use the oil with the minimum viscosity range as the base viscosity is based on the molecular make-up of the oil and the range is achieved by using more additives.



In addition, if you are changing to synthetic you can be less concerned about viscosity breakdown at higher temeratures and mileages.



Just my 2 cents.
 
It won't hurt if the manufacturer recommends it. Shouldn't need to run anything thicker unless you're spraying or boosting. :D
 
i'd stick with the recomended 5w-20.

Im shere there is a reason why Honda recomends 5w-20 over 5w-30.

Mobil 1 is a good oil from what I've been reading. After alot of reserch on motor oils, I've decided on running Mobil 1 synthetic in my Integra GS-R.
 
BTW, Johnny...the old saw about the thinner oils being recommended by the mfrs. for fuel economy reasons dates back to when GM started to recommend 10W-30 instead of 10W-40, and would void your warranty if you didn't use it. Their stated reason was that 10W-40 used too many VI (viscosity index) improvers and that it would sludge up and stick the rings. The unbelievers cried "BS!" and said it was because GM wasn't meeting the (then new) CAFE requirements and they needed to squeak every MPG out of their cars, even if it was to the detriment of engine durability (what did they care, it would be out of warranty by the time the engine blew). Well, that was a really long time ago, and GM has been recommending 5W-30 (OMG!) for a long time.



I don't think Honda, which has, by accounts here, the most fuel efficient fleet out there, needs to compromise engine durability in their premium brand (Acura) for fuel economy reasons, so I call BS on that argument.
 
Looks like I'm going with Mobil 1 5W-20, unless someone else makes a really good argument for the 5W-30. Thanks for all the advice/input :hifive:



yankees: I've heard the Castrol Synthetic (German) which is a real synthetic (group 4) unlike its US counterpart is good, unfortunately I haven't seen it any automotive stores. I've had a hard enough time finding Mobil 1 5W-20, all most stores have are 5W-30 or 10W-30. :(



Setec: I agree with most of your points, but I'm still not 100% sure about the whole fuel efficient thing. I have also been seeing more and more newer cars using the 5W-20 oil instead of the 5W-30, and a couple include these mini suvs, which so happens to be boosting about their great MPG. I also think times are changing a bit with the development of hybrid cars. I feel car manufacturers are going to want to optimize MPG to compete with some of these hybrids, as well try to save on the limited resources we have. I'm probably overthinking this though, and will probably just use the recommended 5W-20.



I guess hypothetically speaking, and correct me if i'm wrong but if the 5W-20 provided less protection than 5W-30, the fact that i'm using a synthetic would counter that a bit as there suppose to provide way more protection than dino oils??? Sorry if I'm offending any oil gurus, I obviously don't know a lot about oils, I'm just basing my assumptions from what I read online.
 
The idea would be that the 30 weight would have a higher film strength, and better be able to separate moving parts. Although the M1 would be more resistant to breakdown, it won't have the film strength of a higher viscosity oil. IMO, no self-respecting Honda engineer would let the MPG dorks compromise the integrity of his engine by putting too thin an oil in there. If Honda puts 5W-20 on the fill cap, you can bet it's designed to run fine on 20 weight oil.



I think you ARE overthinking it...if mfrs are recommending 5W-20 for fuel economy purposes, it's because they have designed the engines to run on 20 weight oil to take advantage of the potential fuel savings, not like the grease monkey at the end of the line is putting 20 weight in because some bean counter/ad mgr. told him to.
 
I use to work at a mazda dealership as a tech. The mazda mpv took 5w-20 but we had a couple come back with blown engines. Some said it was due to the customers using 10w-30 which made the oil pumps work at to high psi? I say use 5w-20 mobil one.
 
Setec Astronomy said:
I think you ARE overthinking it...if mfrs are recommending 5W-20 for fuel economy purposes, it's because they have designed the engines to run on 20 weight oil to take advantage of the potential fuel savings, not like the grease monkey at the end of the line is putting 20 weight in because some bean counter/ad mgr. told him to.
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Haha OK OK I give up, no more debate, 5W-20 it is. I'll put my trust in the engineers at Honda.

Besides I have more important things to worry about, I got my intro and lit review for my senior research project due Thursday, and I'm pretty behind :bolt :help:



Datsun: Thanks for sharing your experience, I have yet to read anything negative about using different weights until I read your post. Definately don't want to blow the engine :nervous2:
 
the idea between weights of oil, as i understand it, is the number represent the oil's operating range of viscocity.



The ranges are determined by how many different chemical additives are put in to make the oil operate within a viscocity range. example, a 10-30 has fewer additives than 5-30. Most mechanics & tuners I know have stated the fewer additives the better quality of oil...(when choices are available)
 
Frankly you can use either one but the M1 0W20 or 5W20 oils are superb so why mess with success?



M1's 5W30 is just barely a 30 weight oil so the car wouldn't know the difference and warranty would not be affected. Having said that, I stick with M1 0W20 API SL, I bought quite a bit before the new SM designation was on the shelves.



Use the 20 weights with confidence - Thin is in!
 
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