Over thinking engine oil - MPG related

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Originally Posted By: D189379
I bet the extra engine wear from using a lighter weight oil is as insignificant as the 1% mileage you gain. Who cares? Clearly lighter oils don't destroy engines, nor do they save you huge amounts of fuel.
Your post is funny. Clearly, thinner oils don't destroy engines which spec a thin oil. AGREED Will a 5w30 cause more wear in a performance engine which specs 5w40? MOST LIKELY I wish the world wasn't in an oil crisis that it's in today where automakers could use whatever oil viscosity they want (if they were interested in keeping the engine running forever vs basically forcing you to come back and buy a new when your current engine blows) as it would be interesting to see which direction the oil viscosity trend would be heading... North or South.
 
Originally Posted By: chubbs1
Very few people use 0w20 when their car calls for 5w30. Am I missing something?
Yes you are... case in point.
Originally Posted By: jsinton
My question is what kind of mpg improvement should I expect with a 0w-20 over a 5w-30? The M1 website seems to indicate I can use 0w-20 in my poor old Hyundai Elantra. I've been using 5w-30 full synthetic with I think is terrific results. I'm looking for better mpg. Can I use this oil without toasting my motor? I live in Florida.
^Quote pulled from "Any Reason TO NOT USE A 0w-XX oil" thread from the last page. Lets not focus on the 0w part and only look at the 20 vs 30 grade in question.
 
Originally Posted By: Artem
.......... i'm not upping the viscosity from the factory 5w30 i'm simply looking for an oil that will maintain its viscosity over the course of an OCI. (A more robust, sheer stable oil)..............
Have you found that shear stable 5W30 oil yet?
 
Originally Posted By: Artem
Originally Posted By: D189379
I bet the extra engine wear from using a lighter weight oil is as insignificant as the 1% mileage you gain. Who cares? Clearly lighter oils don't destroy engines, nor do they save you huge amounts of fuel.
Your post is funny. Clearly, thinner oils don't destroy engines which spec a thin oil. AGREED Will a 5w30 cause more wear in a performance engine which specs 5w40? MOST LIKELY I wish the world wasn't in an oil crisis that it's in today where automakers could use whatever oil viscosity they want (if they were interested in keeping the engine running forever vs basically forcing you to come back and buy a new when your current engine blows) as it would be interesting to see which direction the oil viscosity trend would be heading... North or South.
+1 Artem. That is really what I would like to know. I am just trusting the engineers. I totally understand your point. I too am surprised when I see trucks spec'd for 5w20 (even 0w20 for new Tundras') I would be uncomfortable using 0w20 while I am towing a 25ft boat. Maybe it is just ingrained to expect to use a heavier wgt. in those conditions, or CAFE? Like you said who's best interests are important: the gov and Car manufacturers, or the consumer?
 
My current fill of Redline 5w30 is almost ready to sample @ 3k to compare the shearing to that of M1 and Amsoil. I have another 80 miles before hitting the infamous 3,000 miles mark and pulling a sample. Stay tuned for updates. I plan to keep trying different brands of "supposed" shear stable oils to find as many good brands as possible.
 
When i first got my escape i tried the 5w 20 in it. It was fine cold but noisy when hot and not as smooth. I changed it to 5w 30 much better, quiet when hot. I did some towing and ran an oci of 5w 40 rotella. Currently i run m1 0w 30 this has been the best smoothest running oil so far. I saw no fuel mileage difference in the 20 30 or 40wt oils they all got the same fuel mileage. btw the escape is spec'd for 5w 20. It has been run the last 100k on 30 and 40 wt oils with no ill effects and no loss of mpg.
 
eljefino, well said. The OP hasn't mentioned oil pressure or oil temp's once in his diatribe. You want the oil to be as light as possible and just as thick as necessary. And how thick is necesary? I'd say 3.5cP would be satisfactory for most engines. Even with a light 20wt oil, the oil temp's have to be a fair bit higher than 100C for the in bearing viscosity to drop that low. The main point is that there is a zero increase in engine wear at operating temp's with a light oil over a grade or two thicker oil as long as that minimum in bearing viscosity is maintained. The main reason a mfter can spec' a 20wt oil is because they have the oil temp's well under control even in extreme applications. The reason 30wt and heavier oils are specified by some mfters is because higher oil temp's "may" occur or the oil may loose viscosity for other reasons such as oil shear or the possibility of fuel dilution. Can you run a 20wt oil in an engine for which a heavier oil is specified? The answer is often yes in normal NA street use applications because normally oil temp's simply don't get high enough to actually warrant the heavier specified oil. That doesn't mean I recommend running a lighter than specified oil for the average driver; I don't unless your vehicle is equipped with oil gauges and you fully know what your doing.
 
Originally Posted By: chubbs1
Originally Posted By: Artem
Originally Posted By: D189379
I bet the extra engine wear from using a lighter weight oil is as insignificant as the 1% mileage you gain. Who cares? Clearly lighter oils don't destroy engines, nor do they save you huge amounts of fuel.
Your post is funny. Clearly, thinner oils don't destroy engines which spec a thin oil. AGREED Will a 5w30 cause more wear in a performance engine which specs 5w40? MOST LIKELY I wish the world wasn't in an oil crisis that it's in today where automakers could use whatever oil viscosity they want (if they were interested in keeping the engine running forever vs basically forcing you to come back and buy a new when your current engine blows) as it would be interesting to see which direction the oil viscosity trend would be heading... North or South.
+1 Artem. That is really what I would like to know. I am just trusting the engineers. I totally understand your point. I too am surprised when I see trucks spec'd for 5w20 (even 0w20 for new Tundras') I would be uncomfortable using 0w20 while I am towing a 25ft boat. Maybe it is just ingrained to expect to use a heavier wgt. in those conditions, or CAFE? Like you said who's best interests are important: the gov and Car manufacturers, or the consumer?
You can pretty much throw the consumer part out the window because that is not the main concern of either the government nor the automaker. Right now, its all about saving our valuable resources but the question is, are we putting our engines at the front of the battle to take the hit or are engines and oil technology reached a point that we can use 0w10 next year and not worry about back tracking the oil grade and recommend that much older cars from the 90s are perfectly fine to use a thinner 5w20 in and engine originally asking for 5w30 or 10w30 as an option.
 
Originally Posted By: CATERHAM
eljefino, well said. The OP hasn't mentioned oil pressure or oil temp's once in his diatribe. You want the oil to be as light as possible and just as thick as necessary. And how thick is necesary? I'd say 3.5cP would be satisfactory for most engines. Even with a light 20wt oil, the oil temp's have to be a fair bit higher than 100C for the in bearing viscosity to drop that low. The main point is that there is a zero increase in engine wear at operating temp's with a light oil over a grade or two thicker oil as long as that minimum in bearing viscosity is maintained. The main reason a mfter can spec' a 20wt oil is because they have the oil temp's well under control even in extreme applications. The reason 30wt and heavier oils are specified by some mfters is because higher oil temp's "may" occur or the oil may loose viscosity for other reasons such as oil shear or the possibility of fuel dilution. Can you run a 20wt oil in an engine for which a heavier oil is specified? The answer is often yes in normal NA street use applications because normally oil temp's simply don't get high enough to actually warrant the heavier specified oil. That doesn't mean I recommend running a lighter than specified oil for the average driver; I don't unless your vehicle is equipped with oil gauges and you fully know what your doing.
Unfortunately, what i'm seeing more and more these days is... QUESTION: Can i use this 5w20 oil i got that's been laying in my garage for a while in my car that specs 5w30? ANSWER: Sure!
 
Originally Posted By: spasm3
When i first got my escape i tried the 5w 20 in it. It was fine cold but noisy when hot and not as smooth. I changed it to 5w 30 much better, quiet when hot. I did some towing and ran an oci of 5w 40 rotella. Currently i run m1 0w 30 this has been the best smoothest running oil so far. I saw no fuel mileage difference in the 20 30 or 40wt oils they all got the same fuel mileage. btw the escape is spec'd for 5w 20. It has been run the last 100k on 30 and 40 wt oils with no ill effects and no loss of mpg.
Kinda hard to believe that you're not seeing a decline in gas mileage by using a 30 or 40 grade in an engine asking for 20 but i'll take your word on it. I also noticed smoother / quieter engine operations when revving my Engine past 8,000 RPM while using a 40 grade oil. (NOTE: ONLY while revving past the factory rev limit of 8,000RPM in my modified engine) Gas mileage suffered big time with the heavier oil.
 
Originally Posted By: Artem
Originally Posted By: spasm3
When i first got my escape i tried the 5w 20 in it. It was fine cold but noisy when hot and not as smooth. I changed it to 5w 30 much better, quiet when hot. I did some towing and ran an oci of 5w 40 rotella. Currently i run m1 0w 30 this has been the best smoothest running oil so far. I saw no fuel mileage difference in the 20 30 or 40wt oils they all got the same fuel mileage. btw the escape is spec'd for 5w 20. It has been run the last 100k on 30 and 40 wt oils with no ill effects and no loss of mpg.
Kinda hard to believe that you're not seeing a decline in gas mileage by using a 30 or 40 grade in an engine asking for 20 but i'll take your word on it. I also noticed smoother / quieter engine operations when revving my Engine past 8,000 RPM while using a 40 grade oil. (NOTE: ONLY while revving past the factory rev limit of 8,000RPM in my modified engine) Gas mileage suffered big time with the heavier oil.
I'm thinking that in larger engines it is too small of an effect, perhaps in 4 cyl or engines of low output it may show up in higher mpg.
 
Originally Posted By: spasm3
Originally Posted By: Artem
Originally Posted By: spasm3
When i first got my escape i tried the 5w 20 in it. It was fine cold but noisy when hot and not as smooth. I changed it to 5w 30 much better, quiet when hot. I did some towing and ran an oci of 5w 40 rotella. Currently i run m1 0w 30 this has been the best smoothest running oil so far. I saw no fuel mileage difference in the 20 30 or 40wt oils they all got the same fuel mileage. btw the escape is spec'd for 5w 20. It has been run the last 100k on 30 and 40 wt oils with no ill effects and no loss of mpg.
Kinda hard to believe that you're not seeing a decline in gas mileage by using a 30 or 40 grade in an engine asking for 20 but i'll take your word on it. I also noticed smoother / quieter engine operations when revving my Engine past 8,000 RPM while using a 40 grade oil. (NOTE: ONLY while revving past the factory rev limit of 8,000RPM in my modified engine) Gas mileage suffered big time with the heavier oil.
I'm thinking that in larger engines it is too small of an effect, perhaps in 4 cyl or engines of low output it may show up in higher mpg.
Perhaps. Maybe upping a single grade won't absolutely KILL the gas mileage but jumping 2 full grades should've at least lowered your ave a few points (unless for some reason, weather conditions got better and/or you starting driving more efficiently and covered up the mileage loss due the oil viscosity. shrug I wonder what benefit your engine saw with the thicker oils. Obviously Ford designed the block to run on the 20 grade all while towing a few thousand pounds.
 
eh, as long as its still a light 40 weight at the end of the day (after all the abuse i manage to put it through) i would have succeeded in my pursuit of finding a shear stable oil. If it would make you happy, i'd gladly order some Redline 5w20 (is it in fact a light 30 grade?) just to stay within the 5w30 spec the previous oils in my UOA were. The point isn't what viscosity it is, its finding a SHEAR STABLE oil. Do people not read these days? duh P.S. I want to add that i did in fact note worse gas mileage while using Redline 5w30 for the last 3,000 miles (noted with each and every tank full) so your post regarding that its a heavy 30 grade is true (or i'm just running the car even harder then i already do, just to give Redline a good work out, i haven't decided yet. popcorn
 
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Originally Posted By: Artem
The point isn't what viscosity it is, its finding a SHEAR STABLE oil. Do people not read these days? duh
A target minimum operational viscosity should be the point not whether an oil is shear stable. When a mfter spec's an oil grade a certain amount of shear is expected and allowed for. For example Porsche sets the limit a 15% before an oil is condemned. There of course is nothing wrong with desiring a shear stable oil but you should have a target operational viscosity in mind otherwise virtually by def'n you'll be running a heavier than necessary oil. And the only way to know what your target operational viscosity is is with an oil pressure gauge. Since we're talking about RL, I'd never recommend their 5W-20 (which is a mid-grade 30wt with it's HTHS vis of 3.3cP) oil for any application due to it's pathetically low VI of 145 and because their slightly lighter 0W-30 is such superior product. Since Honda spec's a light 30wt for the Si, RL's 0W-20 would be the most appropriate choice. It's VII free (shear proof), has a HTHS vis' probabily higher than the claimed 2.7cP and will no doubt provide more than adequate OP and therefore operational viscosity even under the hottest conditions. Using RL 0W-20 would also be consistent with RL's recommendation of dropping a grade when switching to their products.
 
Originally Posted By: Artem
Originally Posted By: D189379
I bet the extra engine wear from using a lighter weight oil is as insignificant as the 1% mileage you gain. Who cares? Clearly lighter oils don't destroy engines, nor do they save you huge amounts of fuel.
Your post is funny. Clearly, thinner oils don't destroy engines which spec a thin oil. AGREED Will a 5w30 cause more wear in a performance engine which specs 5w40? MOST LIKELY I wish the world wasn't in an oil crisis that it's in today where automakers could use whatever oil viscosity they want (if they were interested in keeping the engine running forever vs basically forcing you to come back and buy a new when your current engine blows) as it would be interesting to see which direction the oil viscosity trend would be heading... North or South.
I think you're being a bit dramatic. I don't think engine longevity is suffering (in any measurable amount) from the switch to 20 weight oils. Has there been some sort of epidemic of 20W spec'd Honda and Toyota engines that are failing prematurely that I haven't heard about? If I'm wrong I'd love to know about this. It sounds very dangerous.
 
i don't know what to say to that. I called Redline and the tech told me 5w30 is what i need for my Modified K series engine. I don't understand all the HTHS cP viscosity ratings but if is says 5w20 on the bottle, i take it as a 20 grade (it can be on the quick or thin side of things, its still a 20 grade at the end of the day (or will shear down into it within a few miles on use)) and hence, labeled as such. I'm not experimenting with oils based on the HTHS cP rating but based on what's on the bottle. What Honda originally spec'd for the engine doesn't apply to me because my engine is modified and produces more power then the stock rating. I'm also not interested in using a thin 30 grade for MPGs sake. I'm interested in good engine protection while spinning the engine to 8,600 RPM while still trying to maintain decent gas mileage. Seeing as both M1 and Amsoil's best sheared into a thick 20 grade, its no good to me.
 
Originally Posted By: SrDriver
We experience long hot Summers here in south Alabama and all I know is the Ford Police Cars here run 5W20 oil and you know the abuse they receive. We use it in our Two vehicles and did likewise in the Two previous ones. Nothing has blown up yet that I know of!
Same down here..All our 4.6 Panthers have been running 5W20 from day 1. I will let everyone here know when the Ford Police Interceptors and the Dodge Hemis start dropping dead on the side of the road in Miami-Dade and Broward County.
 
Originally Posted By: D189379
I think you're being a bit dramatic. I don't think engine longevity is suffering (in any measurable amount) from the switch to 20 weight oils. Has there been some sort of epidemic of 20W spec'd Honda and Toyota engines that are failing prematurely that I haven't heard about? If I'm wrong I'd love to know about this. It sounds very dangerous.
You're talking about engines which spec a 20 grade from the factory. I'm talking about using a 20 grade in an engine original designed to run on a 30 grade. I never once mentioned complete premature engine failure while using thin oils in even in engines originally asking for thicker juice. I said increased wear! there's a difference.
 
Originally Posted By: CROWNVIC4LIFE
Originally Posted By: SrDriver
We experience long hot Summers here in south Alabama and all I know is the Ford Police Cars here run 5W20 oil and you know the abuse they receive. We use it in our Two vehicles and did likewise in the Two previous ones. Nothing has blown up yet that I know of!
Same down here..All our 4.6 Panthers have been running 5W20 from day 1. I will let everyone here know when the Ford Police Interceptors and the Dodge Hemis start dropping dead on the side of the road in Miami-Dade and Broward County.
Lol. I highly doubt those engine will start failing due to running the factory spec'd 5w20
Originally Posted By: Artem
For some reason i always crackmeup when someone is looking to "squeeze" out a measly 1 or 2% (if that) better gas mileage out of their car by turning to thinner oil as the solution.
 
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