Mobil 15w50 in 0w20 engine.
- Thread starter Graham Piccinini
- Start date
- Status
Originally Posted By: Vlad_the_Russian
My engine's oil cap recommendation states 0w20. I have been using Pennzoil 0w40 SRT for quite some time. Last oil change I switched to Mobil 1 15w50, just for S&G. I drive a lot and have a lot of idling time too. On average I go through 1 tank of gas per day. So if any changes take place - I notice them right away and can confirm if the change is permanent, or a one-time spike.
Here are the results of Mobil1 15w50 in 2009 Scion xB:
- Fuel economy did not take a hit over the past 7 tanks of gas, compared to the SRT 0w40. I was surprised, because I was under the impression that SRT 0w40 is a very "light" 40w and the 15w50 is a very "heavy" 50w. Expected an MPG drop, but that did not happen.
- Really enjoying the smoothness of throttle response in the lower RPM range. Feels like the engine gained some torque. Can't explain why... Better ring seal?... BUT hate the slight HP loss in the upper RPM range. Very minor, but the loss is there.
I will run this oil for 7k miles (my longest OCI yet in this vehicle) and will send it off for a UOA.
Im sure you will end up with a good UOA. 50 seems a bit heavy to me, then again, it doesnt really matter and the 15/50 isnt really all that heavy.
One thing for sure, I think its nuts to run a /020 or 5/20. 20 weight oils are for nothing more then the wackjobs in the US government.
I would simply stick to a 30 though or your 0/40, think a case could be made for 15/50 in a warm climate but I wouldnt do it ... maybe!
My engine's oil cap recommendation states 0w20. I have been using Pennzoil 0w40 SRT for quite some time. Last oil change I switched to Mobil 1 15w50, just for S&G. I drive a lot and have a lot of idling time too. On average I go through 1 tank of gas per day. So if any changes take place - I notice them right away and can confirm if the change is permanent, or a one-time spike.
Here are the results of Mobil1 15w50 in 2009 Scion xB:
- Fuel economy did not take a hit over the past 7 tanks of gas, compared to the SRT 0w40. I was surprised, because I was under the impression that SRT 0w40 is a very "light" 40w and the 15w50 is a very "heavy" 50w. Expected an MPG drop, but that did not happen.
- Really enjoying the smoothness of throttle response in the lower RPM range. Feels like the engine gained some torque. Can't explain why... Better ring seal?... BUT hate the slight HP loss in the upper RPM range. Very minor, but the loss is there.
I will run this oil for 7k miles (my longest OCI yet in this vehicle) and will send it off for a UOA.
Im sure you will end up with a good UOA. 50 seems a bit heavy to me, then again, it doesnt really matter and the 15/50 isnt really all that heavy.
One thing for sure, I think its nuts to run a /020 or 5/20. 20 weight oils are for nothing more then the wackjobs in the US government.
I would simply stick to a 30 though or your 0/40, think a case could be made for 15/50 in a warm climate but I wouldnt do it ... maybe!
Last edited:
A 5 or 10w-30 will keep that little motor happy. Try the M1 ESP 5w-30. Save you some time changing oil
In my pre BITOG days I thought that a synthetic 5W-50 was a much better oil than a synthetic 5W-30. I did this for about 2 years in my 1996 2.0L Zetec Contour. I can honestly say it ran. But it felt much slower and my mpg was 4-5 mpg less. Went back to synthetic 5W-30 and my "seat of the pants feel" improved and my "lost" mpg went back up with the 5W-30. I still have the car and it continues to runs great on 5W-30.
Whimsey
Whimsey
Originally Posted By: Whimsey
In my pre BITOG days I thought that a synthetic 5W-50 was a much better oil than a synthetic 5W-30. I did this for about 2 years in my 1996 2.0L Zetec Contour. I can honestly say it ran. But it felt much slower and my mpg was 4-5 mpg less. Went back to synthetic 5W-30 and my "seat of the pants feel" improved and my "lost" mpg went back up with the 5W-30. I still have the car and it continues to runs great on 5W-30.
Whimsey
I had the same experience as you. For a sound engine their is no reason to increase the oil wt. IMO.
In my pre BITOG days I thought that a synthetic 5W-50 was a much better oil than a synthetic 5W-30. I did this for about 2 years in my 1996 2.0L Zetec Contour. I can honestly say it ran. But it felt much slower and my mpg was 4-5 mpg less. Went back to synthetic 5W-30 and my "seat of the pants feel" improved and my "lost" mpg went back up with the 5W-30. I still have the car and it continues to runs great on 5W-30.
Whimsey
I had the same experience as you. For a sound engine their is no reason to increase the oil wt. IMO.
Some engines tolerate a wide array of different viscosities, others don't.
OVERKILL
$100 Site Donor 2021
Originally Posted By: FordCapriDriver
Some engines tolerate a wide array of different viscosities, others don't.
They all do, otherwise temperature swings would kill them.
Some engines tolerate a wide array of different viscosities, others don't.
They all do, otherwise temperature swings would kill them.
Well yeah but i mean that even my 1124cc 60 Hp Peugeot seems to run no different on 20W-50 than it did on a 10w40 syn-blend.
OVERKILL
$100 Site Donor 2021
Originally Posted By: FordCapriDriver
Well yeah but i mean that even my 1124cc 60 Hp Peugeot seems to run no different on 20W-50 than it did on a 10w40 syn-blend.
Yeah, the "performance hit" that people speak of seems to really be all over the map
Well yeah but i mean that even my 1124cc 60 Hp Peugeot seems to run no different on 20W-50 than it did on a 10w40 syn-blend.
Yeah, the "performance hit" that people speak of seems to really be all over the map
Originally Posted By: OVERKILL
Originally Posted By: FordCapriDriver
Some engines tolerate a wide array of different viscosities, others don't.
They all do, otherwise temperature swings would kill them.
Thank you, thank you and THANK YOU!
Originally Posted By: FordCapriDriver
Some engines tolerate a wide array of different viscosities, others don't.
They all do, otherwise temperature swings would kill them.
Thank you, thank you and THANK YOU!
Originally Posted By: FordCapriDriver
In South America, Africa, South east Asia, they put Mineral 20W-50 into [censored] near anything with an internal combustion engine.
In fact in Sotuh America you will find most high mileage oils are 25W-50 or even 25W-60 oils!, but in a tropical climate near the equator where there aren't 4 defined seasons it likely doesn't matter that much as the temperature fluctuations are rather small.
I hear that. Here is the oil recommendation page for a 2015 Yaris 1.2L in Thailand. The 10w-30 note off to the side references "can make the motor sticky in cold weather" when translated by my wife who has not a clue about oil. The warranty is up in December. I'll be going with a 10W-30 at that time since there is no such thing cold weather in southern Thailand. It's had Toyota Full Syn 0W-20 since new done at the dealership.
In South America, Africa, South east Asia, they put Mineral 20W-50 into [censored] near anything with an internal combustion engine.
In fact in Sotuh America you will find most high mileage oils are 25W-50 or even 25W-60 oils!, but in a tropical climate near the equator where there aren't 4 defined seasons it likely doesn't matter that much as the temperature fluctuations are rather small.
I hear that. Here is the oil recommendation page for a 2015 Yaris 1.2L in Thailand. The 10w-30 note off to the side references "can make the motor sticky in cold weather" when translated by my wife who has not a clue about oil. The warranty is up in December. I'll be going with a 10W-30 at that time since there is no such thing cold weather in southern Thailand. It's had Toyota Full Syn 0W-20 since new done at the dealership.
Gotta love how overseas, cars have 5 or 6 different grades listed.
Here, cars will have one grade you can run or drop dead.
Here, cars will have one grade you can run or drop dead.
Originally Posted By: Vlad_the_Russian
- Really enjoying the smoothness of throttle response in the lower RPM range. Feels like the engine gained some torque. Can't explain why... Better ring seal?... BUT hate the slight HP loss in the upper RPM range. Very minor, but the loss is there.
According to the fundamental curve of lubrication -- Stribeck curve -- minimum oil-film thickness (MOFT) and friction increase with viscosity (n [eta]) and RPM (v) and decrease with engine load (P) in the hydrodynamic region. Therefore, it makes sense that you see more effect at high RPM than at low RPM. However, I don't know how you control RPM for a given engine load if you don't have a manual transmission.
It makes little or no sense that the engine gained HP at low RPM with thicker oil. The only way that would happen is that your engine is running in the boundary region -- metal-to-metal contact -- and about to fail. I take the more plausible explanation that it's merely a subjective, psychological observation.
Your MPG didn't change going to a thicker oil? Given how impossibly difficult it is to measure MPG, no one here would believe that.
Toyota engines can tolerate pretty much any viscosity. However, as most people here said, you will gain no benefit from running such an unnecessarily thick oil. Your oil temperature and pressure will be unnecessarily high. You will lose HP and MPG regardless of RPM. Wear-protection benefits? You will be lucky if thicker oil actually doesn't end up producing more wear. Simply run the recommended oil for the most HP, MPG, and probably the longevity as well.
Someone here posted that all engines with a carburetor must run 20W-50. I laugh at such old wives' tales posted on the Internet. I run 0W-20 in a 1985 engine with a carburetor with no problems. Fuel dilution? I've never experienced it.
- Really enjoying the smoothness of throttle response in the lower RPM range. Feels like the engine gained some torque. Can't explain why... Better ring seal?... BUT hate the slight HP loss in the upper RPM range. Very minor, but the loss is there.
According to the fundamental curve of lubrication -- Stribeck curve -- minimum oil-film thickness (MOFT) and friction increase with viscosity (n [eta]) and RPM (v) and decrease with engine load (P) in the hydrodynamic region. Therefore, it makes sense that you see more effect at high RPM than at low RPM. However, I don't know how you control RPM for a given engine load if you don't have a manual transmission.
It makes little or no sense that the engine gained HP at low RPM with thicker oil. The only way that would happen is that your engine is running in the boundary region -- metal-to-metal contact -- and about to fail. I take the more plausible explanation that it's merely a subjective, psychological observation.
Your MPG didn't change going to a thicker oil? Given how impossibly difficult it is to measure MPG, no one here would believe that.
Toyota engines can tolerate pretty much any viscosity. However, as most people here said, you will gain no benefit from running such an unnecessarily thick oil. Your oil temperature and pressure will be unnecessarily high. You will lose HP and MPG regardless of RPM. Wear-protection benefits? You will be lucky if thicker oil actually doesn't end up producing more wear. Simply run the recommended oil for the most HP, MPG, and probably the longevity as well.
Someone here posted that all engines with a carburetor must run 20W-50. I laugh at such old wives' tales posted on the Internet. I run 0W-20 in a 1985 engine with a carburetor with no problems. Fuel dilution? I've never experienced it.
Originally Posted By: Gokhan
You will be lucky if thicker oil actually doesn't end up producing more wear.
..........
I laugh at such old wives' tales posted on the Internet.
.........
I run 0W-20 in a 1985 engine with a carburetor
So you say a thicker oil can produce more wear, based on what ? It needs to be better than two simple UOAs from your 1985 Toyota 4-cylinder.
Sounds like you are trying to start a few new wives' tales of your own.
You will be lucky if thicker oil actually doesn't end up producing more wear.
..........
I laugh at such old wives' tales posted on the Internet.
.........
I run 0W-20 in a 1985 engine with a carburetor
So you say a thicker oil can produce more wear, based on what ? It needs to be better than two simple UOAs from your 1985 Toyota 4-cylinder.
Sounds like you are trying to start a few new wives' tales of your own.
I run 0w20 in my mini van that calls for 5w30 and I have noticed nothing but good. So much smoother and the throttle response is somehow much better. I have not preformed any UOA comparisons but I am so far a believer.
Next I will be switching my truck that calls for 10w30 to a good 0w20 and hope for similar results.
Next I will be switching my truck that calls for 10w30 to a good 0w20 and hope for similar results.
For what it's worth, I ran Castrol 5W-50 in my 1991 Previa for its entire life (I was the original owner). I changed the oil every 7,500 miles (just when the change oil light said to) and it had 238,000 miles on it when I sold it. Ran fine and never burned oil.
Last edited:
Originally Posted By: TheKracken
I run 0w20 in my mini van that calls for 5w30 and I have noticed nothing but good. So much smoother and the throttle response is somehow much better. I have not preformed any UOA comparisons but I am so far a believer.
Next I will be switching my truck that calls for 10w30 to a good 0w20 and hope for similar results.
When I first bought my 2007 Fusion 2.3 I put 5-30 M1 EP in it. I drove maybe two 10K OCIs then switched to M1 5-20 for one OCI then to M1 0-20AFE. I did see a uptick in MPG and the engine seemed to be more responsive with the 20wt oils.
I run 0w20 in my mini van that calls for 5w30 and I have noticed nothing but good. So much smoother and the throttle response is somehow much better. I have not preformed any UOA comparisons but I am so far a believer.
Next I will be switching my truck that calls for 10w30 to a good 0w20 and hope for similar results.
When I first bought my 2007 Fusion 2.3 I put 5-30 M1 EP in it. I drove maybe two 10K OCIs then switched to M1 5-20 for one OCI then to M1 0-20AFE. I did see a uptick in MPG and the engine seemed to be more responsive with the 20wt oils.
Last edited:
Originally Posted By: tig1
Originally Posted By: TheKracken
I run 0w20 in my mini van that calls for 5w30 and I have noticed nothing but good. So much smoother and the throttle response is somehow much better. I have not preformed any UOA comparisons but I am so far a believer.
Next I will be switching my truck that calls for 10w30 to a good 0w20 and hope for similar results.
When I first bought my 2007 Fusion 2.3 I put 5-30 M1 EP in it. I drove maybe two 10K OCIs then switched to M1 5-20 for one OCI then to M1 0-20AFE. I did see a uptick in MPG and the engine seemed to be more responsive with the 20wt oils.
How would you describe your driving style?
Originally Posted By: TheKracken
I run 0w20 in my mini van that calls for 5w30 and I have noticed nothing but good. So much smoother and the throttle response is somehow much better. I have not preformed any UOA comparisons but I am so far a believer.
Next I will be switching my truck that calls for 10w30 to a good 0w20 and hope for similar results.
When I first bought my 2007 Fusion 2.3 I put 5-30 M1 EP in it. I drove maybe two 10K OCIs then switched to M1 5-20 for one OCI then to M1 0-20AFE. I did see a uptick in MPG and the engine seemed to be more responsive with the 20wt oils.
How would you describe your driving style?
Originally Posted By: SilverFusion2010
Originally Posted By: tig1
Originally Posted By: TheKracken
I run 0w20 in my mini van that calls for 5w30 and I have noticed nothing but good. So much smoother and the throttle response is somehow much better. I have not preformed any UOA comparisons but I am so far a believer.
Next I will be switching my truck that calls for 10w30 to a good 0w20 and hope for similar results.
When I first bought my 2007 Fusion 2.3 I put 5-30 M1 EP in it. I drove maybe two 10K OCIs then switched to M1 5-20 for one OCI then to M1 0-20AFE. I did see a uptick in MPG and the engine seemed to be more responsive with the 20wt oils.
How would you describe your driving style?
I dont drive any of my vehicles hard. Lots of short trips as well. I also drive slow in the right lane of the highway....
Originally Posted By: tig1
Originally Posted By: TheKracken
I run 0w20 in my mini van that calls for 5w30 and I have noticed nothing but good. So much smoother and the throttle response is somehow much better. I have not preformed any UOA comparisons but I am so far a believer.
Next I will be switching my truck that calls for 10w30 to a good 0w20 and hope for similar results.
When I first bought my 2007 Fusion 2.3 I put 5-30 M1 EP in it. I drove maybe two 10K OCIs then switched to M1 5-20 for one OCI then to M1 0-20AFE. I did see a uptick in MPG and the engine seemed to be more responsive with the 20wt oils.
How would you describe your driving style?
I dont drive any of my vehicles hard. Lots of short trips as well. I also drive slow in the right lane of the highway....
- Status
Similar threads
