as I was trying to convince myself to use a 5w30 in place of a 5w20 I was thinking no I shouldn't due to 5w30 being thicker but then it hit me. The difference between an allowable 9.3cst at temperature and say a 5w30 that runs at 10.5 cat is not that much of a difference when you consider the entire time an engine is warming up its running at 50, 40, 30, 20 and so on CST.... Am i missing something here? I mean if a car can survive years of "warming up" where the oil is much thicker with seemingly no problem than there really shouldn't be much difference at all between say a light for spec 5w30 and a thick for spec 5w20 right? I mean my car running 5w20 during short trips for the past 10 years must have spent countless hours running super thick oil with no problem... Tell me if I am missing something here? This isn't even taking into account that over an OCI a 5w30 could likely shear down a bit making it even thinner than when it started. I guess I really can't see the big deal with running a 5w30 in place of 5w20 even though my mechanic said i shouldn't and that the honda cars are designed for the thinner oil.
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Mechanic probably wouldn't know. Go for it... I switched and liked results...
xW-20 isn't even available in many countries where the same Honda with the same engine is sold.
Mechanics tend to go with whatever is on the fill cap or what their computer or a book says the vehicle takes. They don't like to use fluids or filters that aren't expressly recommended for the vehicle because they have to warranty their work.
good points. Its strange how I never even considered the difference between cool not even cold but cool oil temp viscosity and operating temp. I mean if the big deal is that somehow the tolerances can't handle it than what about all the time spent at 20 or 30 CST during warm up right?
My reasoning was always 5w30 and 5w20 are still a 5 at that start. So 5w30 does nothing more that surpass a thicker oil, its like 5w20 plus. The same people mind nothing with going thinner with 0w20, but think their engine may not even turn over if they go any thicker. You may be surprised to learn as I have learned through experience, not hypothetical as a lot of people on here do. My gas mileage didn't change with 10w30/ 5w30 or 5w20.
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If there "isn't that much difference," the argument could go both ways.
I don't see an issue with either.
I don't see an issue with either.
In Australia, the standard oil that is used in the same Honda Odyssey is the rather thick 15W-40. Therefore, using the already rather thin ILSAC 5W-30 is hardly any different than using the a little thinner 5W-20.
http://www.ozhonda.com/forum/showthread.php?126498-What-engine-oil-for-3rd-gen-Honda-Odyssey
http://www.ozhonda.com/forum/showthread.php?126498-What-engine-oil-for-3rd-gen-Honda-Odyssey
Jake777, that is physical reality. On the way to full hot running temperatures, an oil keeps thinning out more and more. This takes a while, so the engine must cope well with thick or even very thick oil for several minutes at least.
Also, if you drop your peak hot oil temperature by about 20 degrees or so, its like using a thicker oil SAE grade in your engine.
So a car that specs a 20 can use a 30 no problem.
Trouble might happen if a car that specs a 30 gets a 20 oil, since the oil may thin out too much hot to have a sufficient oil film and to operate the valve timing hydraulics.
The idea is to use an oil that is the thinnest recommended for your application for best fuel economy (lower viscous drag) while not too thin to maintain a minimum oil film thickness during the hottest possible conditions.
Also, if you drop your peak hot oil temperature by about 20 degrees or so, its like using a thicker oil SAE grade in your engine.
So a car that specs a 20 can use a 30 no problem.
Trouble might happen if a car that specs a 30 gets a 20 oil, since the oil may thin out too much hot to have a sufficient oil film and to operate the valve timing hydraulics.
The idea is to use an oil that is the thinnest recommended for your application for best fuel economy (lower viscous drag) while not too thin to maintain a minimum oil film thickness during the hottest possible conditions.
so for safety measure going with 5w30 might be better.... I want to run this motor for years more and if a slightly thicker oil provides better boundary protection why not use it.. Thanks for all the responses. As for the person who says it could go either way about why not just use the 20 I say I would rather lean on the protective side than the MPG side. By the way thanks for the link Gokhan. It was actually your post earlier that got me thinking.
In the U.S. anyway, when I see an application that is approved by the manufacturer to use a 20 oil, then I view that as a minimum viscosity. That engine will handle something thicker without issue.
The engineers basically say "This is the thinnest oil we think will maintain a sufficient oil film." Since they know how hot the oil gets, and the size of the bearings, you know their recommendation is basically the thinnest oil you can use.
Best follow the owner's manual viscosity for maximum fuel economy and acceptably-low engine wear in the U.S. where fuel economy pressure makes the engineers cut viscosity margins to the minimums.
The engineers basically say "This is the thinnest oil we think will maintain a sufficient oil film." Since they know how hot the oil gets, and the size of the bearings, you know their recommendation is basically the thinnest oil you can use.
Best follow the owner's manual viscosity for maximum fuel economy and acceptably-low engine wear in the U.S. where fuel economy pressure makes the engineers cut viscosity margins to the minimums.
Jake777,
that's it exactly...the whole 101 thing of oils being "too thick" to lubricate when cold and during warmup is garbage...
http://www.sae.org/events/pfs/presentations/2005spikes.pdf
Page 14, can see the thickness of the hydrodynamic layer for a given oil at varying temperatures. As per my warm-up wear thread, the cold oils do a good job of keeping parts separated, and the additives do a good job when hot.
The increase in HTHS (2.6 min for a 5W20, they are usually around 2.7. 2.9 min for a 30, they are usually 3.0-3.2) 5W30 will cost you a little (tiny little) in fuel economy, but will have higher hydrodynamic film thicknesses.
They are against the industry reference oils, so you need to do both oils that you are thinking of, and compare the difference.
EFEI (%) = 8.647 - 1.252*HTHS - 15.62*KV100 (Sequence VI)
EFEI(%) = 6.238 - 1.697*HTHS - 4.051*KV100 (Sequence VIA)
Some GM equations
%FE = 2.752 - 0.267*(KV100)
%FE = 3.823 - 1.214*(HTHS) [/quote]
that's it exactly...the whole 101 thing of oils being "too thick" to lubricate when cold and during warmup is garbage...
http://www.sae.org/events/pfs/presentations/2005spikes.pdf
Page 14, can see the thickness of the hydrodynamic layer for a given oil at varying temperatures. As per my warm-up wear thread, the cold oils do a good job of keeping parts separated, and the additives do a good job when hot.
The increase in HTHS (2.6 min for a 5W20, they are usually around 2.7. 2.9 min for a 30, they are usually 3.0-3.2) 5W30 will cost you a little (tiny little) in fuel economy, but will have higher hydrodynamic film thicknesses.
They are against the industry reference oils, so you need to do both oils that you are thinking of, and compare the difference.
EFEI (%) = 8.647 - 1.252*HTHS - 15.62*KV100 (Sequence VI)
EFEI(%) = 6.238 - 1.697*HTHS - 4.051*KV100 (Sequence VIA)
Some GM equations
%FE = 2.752 - 0.267*(KV100)
%FE = 3.823 - 1.214*(HTHS) [/quote]
When I switched to PP 5w20 I started getting a leak around the RMS and the oil pump. When I switched to Pennzoil High Mileage the leak stopped almost completely. I guess I'm now afraid to try a synthetic oil for fear of leaking but would a 5w30 high mileage mobil 1 leak as bad as any other synthetic because its syn properties or would the thicker CST of the 5w30 do the same thing as the Pennzoil High Mileage and slow/stop the leak?
My brother drives a Ford and sister drives a Honda, both spec 5W-20 and have over 100k miles so they burn a bit of oil. I do their oil changes and I use 5W-30 to keep consumption down as they're not the dipstick pulling type. Their engines have not exploded yet.
all the street racers that drive the rice burning civics seem to use the 5w30 with no oil related problems ....Head gaskets are another story.
Most shops doing cheap oil changes usually just dump 5W30 or even 10W30 bulk dino in everything, engines aren't grenading left & right-must not hurt that bad. Shoot, a lot of companies doing their own OCs just dump dual-rated 15W40 in everything with no ill effects!
I've ran 20w50 in my 87 Dodge since it was new and it hasn't blown up yet.
It has ran in temperatures from -15 F to 100+ F.
It has ran in temperatures from -15 F to 100+ F.
Originally Posted By: bullwinkle
Most shops doing cheap oil changes usually just dump 5W30 or even 10W30 bulk dino in everything, engines aren't grenading left & right-must not hurt that bad. Shoot, a lot of companies doing their own OCs just dump dual-rated 15W40 in everything with no ill effects!
This...^^^ think of all of the police fleet cars that get 15w40 for 150,000 and then get 10w30 for another 150,000 when they are Taxis
Most shops doing cheap oil changes usually just dump 5W30 or even 10W30 bulk dino in everything, engines aren't grenading left & right-must not hurt that bad. Shoot, a lot of companies doing their own OCs just dump dual-rated 15W40 in everything with no ill effects!
This...^^^ think of all of the police fleet cars that get 15w40 for 150,000 and then get 10w30 for another 150,000 when they are Taxis
These ain't "thick" oils ... 20W-50, now that is starting to get thicker. Straight 50W is THICK on cold start.
In my world 5W-30 in minimum for winter oils, and 10W-40 for summer. But what the hey, I been running HDEO's for decades in gas burners, so what do I know ... I know I get engines to last well beyond 200,000 miles
Now that we have High Mileage (which more likely means high hours) oils, I'm moving in that direction as seals and gaskets can use help too
In my world 5W-30 in minimum for winter oils, and 10W-40 for summer. But what the hey, I been running HDEO's for decades in gas burners, so what do I know ... I know I get engines to last well beyond 200,000 miles
Now that we have High Mileage (which more likely means high hours) oils, I'm moving in that direction as seals and gaskets can use help too
Originally Posted By: Charlie1935
I've ran 20w50 in my 87 Dodge since it was new and it hasn't blown up yet.
It has ran in temperatures from -15 F to 100+ F.
I did that 20w50 in a 2000 Vtec Civic for 100k and it also didnt had any problems. But lowest temps was about 30F. Sold it and saw it running the other day, fine, no smoke neither noises. 5w30 in FL is water. 20w50 isnt as thick as a straight 30-40-50, when cold.
I've ran 20w50 in my 87 Dodge since it was new and it hasn't blown up yet.
It has ran in temperatures from -15 F to 100+ F.
I did that 20w50 in a 2000 Vtec Civic for 100k and it also didnt had any problems. But lowest temps was about 30F. Sold it and saw it running the other day, fine, no smoke neither noises. 5w30 in FL is water. 20w50 isnt as thick as a straight 30-40-50, when cold.
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