5w-20 or 5w-30?

[Brien]

Wow, oil is getting expensive now!

I have a 2001 Galant with a 2.0. The manual calls for 10w30.

This same engine is also used in the Lancer. In that car it calls for 5w-20.

Would it be incorrect for me to believe that I could use 5w-20?

 

[dparm]

I thought it was a 2.4? The Lancer is probably spec'd for 5w20 for fuel economy reasons, and because it doesn't have to work as hard to move around (lighter car).

 

[Brien]

Whoops, you're right, it is the 2.4l

Interesting about the added weight.

Now I'm curious as to how that'd affect the loads in the engine and if it'd be enough to require a higher viscosity.

 

[Brons2]

10w30 is fine in Florida, I'd stick with the manufacturer recommendation.

 

[CATERHAM]

If it is for fuel economy reasons then yes you likely can use a 20wt oil. At the very least I'd be using a modern 5w30 in the Galant.
Assuming you don't have an oil pressure gauge in you 11 year old Galant, if you drive the car conservatively (slow) with little WOT use then the 20wt oil should be more than fine.

 

[lexus114]

Originally Posted By: CATERHAM
If it is for fuel economy reasons then yes you likely can use a 20wt oil. At the very least I'd be using a modern 5w30 in the Galant.
Assuming you don't have an oil pressure gauge in you 11 year old Galant, if you drive the car conservatively (slow) with little WOT use then the 20wt oil should be more than fine.




You think that would really matter? Not trying to be funny, I`m just curious if that would really matter.

 

[CATERHAM]

Originally Posted By: lexus114
Originally Posted By: CATERHAM

You think that would really matter? Not trying to be funny, I`m just curious if that would really matter.

The truth is you can run a 20 wt oil in most light 30wt street applications. Conservative vehicle operation further minimizes the possibility of high oil temp's and also the viscosity demands of the engine.

 

[LeakySeals]

Originally Posted By: CATERHAM
If it is for fuel economy reasons then yes you likely can use a 20wt oil. At the very least I'd be using a modern 5w30 in the Galant.
Assuming you don't have an oil pressure gauge in you 11 year old Galant, if you drive the car conservatively (slow) with little WOT use then the 20wt oil should be more than fine.


Seems that nearly every recent post on BITOG discusses and recommends using the thinnest possible oils regardless of the age, miles, mechanical condition or type of vehicle. You and a couple others are the only ones that raise the concern over oil pressure. Would be helpful if you could elaborate a little. Many cars do not have oil pressure gauges, just low oil pressure lights. In those cases how would we know that the thin oil recommendations are safe? a used oil analysis before and after?

 

[Brien]

Originally Posted By: LeakySeals
Originally Posted By: CATERHAM
If it is for fuel economy reasons then yes you likely can use a 20wt oil. At the very least I'd be using a modern 5w30 in the Galant.
Assuming you don't have an oil pressure gauge in you 11 year old Galant, if you drive the car conservatively (slow) with little WOT use then the 20wt oil should be more than fine.


Seems that nearly every recent post on BITOG discusses and recommends using the thinnest possible oils regardless of the age, miles, mechanical condition or type of vehicle. You and a couple others are the only ones that raise the concern over oil pressure. Would be helpful if you could elaborate a little. Many cars do not have oil pressure gauges, just low oil pressure lights. In those cases how would we know that the thin oil recommendations are safe? a used oil analysis before and after?


That's what got me to thinking about this. It's time for an oil change.

As you can see, I've been here for ~7 years. I've learned a thing or two. I have never taken the lighter is better pill. I figure it's time to try it.

 

[bepperb]

In Florida sooner or later you're going to be stuck in traffic on a hot piece of tarmac with the a/c running. Whatever advantage you would get from a thinner oil is totally overwhelmed by the small but significant chance you'll get the oil too hot and thin and cause excess wear.

 

[Brien]

Originally Posted By: bepperb
In Florida sooner or later you're going to be stuck in traffic on a hot piece of tarmac with the a/c running. Whatever advantage you would get from a thinner oil is totally overwhelmed by the small but significant chance you'll get the oil too hot and thin and cause excess wear.


That's what I'm unsure about though. There is a huge amount of information talking about how robust 20w oils are.

Heck, I believe the current Gen Mustangs call for 20w don't they?

 

[CATERHAM]

Originally Posted By: LeakySeals
Originally Posted By: CATERHAM
If it is for fuel economy reasons then yes you likely can use a 20wt oil. At the very least I'd be using a modern 5w30 in the Galant.
Assuming you don't have an oil pressure gauge in you 11 year old Galant, if you drive the car conservatively (slow) with little WOT use then the 20wt oil should be more than fine.

Seems that nearly every recent post on BITOG discusses and recommends using the thinnest possible oils regardless of the age, miles, mechanical condition or type of vehicle. You and a couple others are the only ones that raise the concern over oil pressure. Would be helpful if you could elaborate a little. Many cars do not have oil pressure gauges, just low oil pressure lights. In those cases how would we know that the thin oil recommendations are safe? a used oil analysis before and after?

An oil pressure gauge is basically a oil viscosity meter since it measures oil back pressure. Oil temperature is the single biggest factor that affects an oil's viscosity. Even the lightest 0W-20 oil available is too heavy until the bulk sump oil temp's have reached at least 75C. The higher the oil temp's the lower the oil pressure reading. If the specified minimum oil pressure is say 60 psi at elevated rev's then the OP will know if the 10w30 oil he has been running ever has the oil pressure that low. In all likelyhood, even in Florida on the hottest day with the A/C on, he likely hasn't seen his oil pressure below 70 psi. In which case he could try a 20wt oil. Now he might see his oil pressure drop to 65 psi on occation but if it never drops as low as 60 psi he definately can run that 20wt oil.

If the 20wt oil did result in oil pressure that dropped somewhat lower than the 60 psi recommendation then he may still be able to run that oil depending on how often it happens. If it's as soon as the oil is up to normal operating temperature, then it is too light and a heavier 20wt (higher HTHSV) or light 30wt oil is necessary. If it only happens under extreme conditions he could choose to continue to use that oil but avoid high rev's and WOT on the rare occations that the oil gets lighter than he would like.
That's how you fine tune the oil viscosity to your own application.

 

[bepperb]

I agree with all of what you said... except the last sentence.

Really, you're tuning your application so that you can use an arbitrary viscosity... which is the opposite of common sense. Why not just use the manufacturer tested and approved viscosity and not worry about whether you're using too much throttle or turning the a/c off at stoplights?

 

[LeakySeals]

Originally Posted By: CATERHAM
Originally Posted By: LeakySeals
Originally Posted By: CATERHAM
If it is for fuel economy reasons then yes you likely can use a 20wt oil. At the very least I'd be using a modern 5w30 in the Galant.
Assuming you don't have an oil pressure gauge in you 11 year old Galant, if you drive the car conservatively (slow) with little WOT use then the 20wt oil should be more than fine.

Seems that nearly every recent post on BITOG discusses and recommends using the thinnest possible oils regardless of the age, miles, mechanical condition or type of vehicle. You and a couple others are the only ones that raise the concern over oil pressure. Would be helpful if you could elaborate a little. Many cars do not have oil pressure gauges, just low oil pressure lights. In those cases how would we know that the thin oil recommendations are safe? a used oil analysis before and after?

An oil pressure gauge is basically a oil viscosity meter since it measures oil back pressure. Oil temperature is the single biggest factor that affects an oil's viscosity. Even the lightest 0W-20 oil available is too heavy until the bulk sump oil temp's have reached at least 75C. The higher the oil temp's the lower the oil pressure reading. If the specified minimum oil pressure is say 60 psi at elevated rev's then the OP will know if the 10w30 oil he has been running ever has the oil pressure that low. In all likelyhood, even in Florida on the hottest day with the A/C on, he likely hasn't seen his oil pressure below 70 psi. In which case he could try a 20wt oil. Now he might see his oil pressure drop to 65 psi on occation but if it never drops as low as 60 psi he definately can run that 20wt oil.

If the 20wt oil did result in oil pressure that dropped somewhat lower than the 60 psi recommendation then he may still be able to run that oil depending on how often it happens. If it's as soon as the oil is up to normal operating temperature, then it is too light and a heavier 20wt (higher HTHSV) or light 30wt oil is necessary. If it only happens under extreme conditions he could choose to continue to use that oil but avoid high rev's and WOT on the rare occations that the oil gets lighter than he would like.
That's how you fine tune the oil viscosity to your own application.


So its a guess without an oil pressure gauge. And a risk on a 100F day in traffic at the beach. What I wanted to know thanks.

 

[CATERHAM]

Exactly, an OP gauge eliminates all doubt as to whether the oil you're running is to light or thick.

 

[dparm]

Originally Posted By: bepperb
In Florida sooner or later you're going to be stuck in traffic on a hot piece of tarmac with the a/c running. Whatever advantage you would get from a thinner oil is totally overwhelmed by the small but significant chance you'll get the oil too hot and thin and cause excess wear.



In a water cooled car that is insignificant. If it was an air cooled VW or Porsche, then it becomes relevant.

 

[toneydoc]

Follow manufacturer guidelines and you will be fine. FL does not get too cold very often. A lighter oil will increase mileage VERY little. I bet there are many motors in FL that have 100,000 miles plus on them running 30 weight oil.

 

[TFB1]

Originally Posted By: toneydoc
I bet there are many motors in FL that have 100,000 miles plus on them running 30 weight oil.


I know of a 4.6 Ford here in VA that's mostly run 10W-40 for almost 200K... For me oil pressure gauge or not, I'll never risk a oil may not be thick enough... If pressure is about 10psi more than the manufacture's recommendation, I'm happy...

 

[CATERHAM]

Originally Posted By: TFB1
Originally Posted By: toneydoc
I bet there are many motors in FL that have 100,000 miles plus on them running 30 weight oil.

I know of a 4.6 Ford here in VA that's mostly run 10W-40 for almost 200K... For me oil pressure gauge or not, I'll never risk a oil may not be thick enough... If pressure is about 10psi more than the manufacture's recommendation, I'm happy...

An OP gauge has many uses, including informing you if the oil you're using is too thick. If you can't use maximum rev's when the oil is up to normal operating temperature without the oil pump going into by-pass mode; the oil's way too viscose and therefore it's use is counter-productive. And that is almost always the case when running a 40wt oil in a 20wt or even a 30wt application.

 

[lexus114]

Originally Posted By: LeakySeals
Originally Posted By: CATERHAM
If it is for fuel economy reasons then yes you likely can use a 20wt oil. At the very least I'd be using a modern 5w30 in the Galant.
Assuming you don't have an oil pressure gauge in you 11 year old Galant, if you drive the car conservatively (slow) with little WOT use then the 20wt oil should be more than fine.


Seems that nearly every recent post on BITOG discusses and recommends using the thinnest possible oils regardless of the age, miles, mechanical condition or type of vehicle. You and a couple others are the only ones that raise the concern over oil pressure. Would be helpful if you could elaborate a little. Many cars do not have oil pressure gauges, just low oil pressure lights. In those cases how would we know that the thin oil recommendations are safe? a used oil analysis before and after?



Ooh....Ohhhh...I know!!! A flickering oil light @ idle like my old 75 Granada!