Best oil for MPG

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toofastgtp

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I have been feeding my 95' Lexus ES300 PYB 5w30 since i got the car about a year ago (first oil change was Penz plat)

My question is would a different oil help with MPG increase? or should i just keep feeding her PYB? (136k on clock)

95% of all my driving is city and stop and go. Out of a tank i can see anywhere from 16-18mpg.

Plugs, PCV, and fuel filter was done about a year ago. Air filter about 6 months ago.
 
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Hi.

Oil type is even of a less concern than oil viscosity. A synthetic oil is largely marketed to have greater lubricity than conventional. Yes and no. There are too many factors involved in fuel economy that this is insignificant. I would be more concerned about viscosity differences.

I believe that Toyota/Lexus specifies a 5W-30 for that engine, the 1MZ-FE. I personally think you should not deviate any lower from that specification. You can always go higher than the specified (in viscosity), but you should never go lower. Reason being is that, the lower the viscosity, the less film strength that you get at higher operating temperatures. This can lead to a variety of engine problems. In your operating conditions, I think you should keep it as is. 16-18 mpg sounds about right for that engine in city driving. My daily driver is a 1996 Toyota Tacoma V6 4x4. It has the 5VZ-FE (3.4 L), and gets around 15 in the city and about 25 on the highway cruising at 65 mph.

Anyways, back to the viscosity. The differences you see (if any) will be extremely minimal. Fuel economy depends on many more (and greater in magnitude) factors such as the gasoline you use and the condition your car is in...even the weight inside the car too. An oil is a simple fluid; you will notice less than a 1% difference if any.
 
Originally Posted By: toofastgtp
I have been feeding my 95' Lexus ES300 PYB 5w30 since i got the car about a year ago (first oil change was Penz plat)

My question is would a different oil help with MPG increase? or should i just keep feeding her PYB? (136k on clock)

95% of all my driving is city and stop and go. Out of a tank i can see anywhere from 16-18mpg.

Plugs, PCV, and fuel filter was done about a year ago. Air filter about 6 months ago.

If your daily trips are less than 10 miles, the oil almost never get to operating temperature of 200-210F, then you could use xW20. xW20 at 180-190F is as thick as xW30 at 200-210F and much thicker than xW30 at 220-230F.
 
Originally Posted By: HTSS_TR
Originally Posted By: toofastgtp
I have been feeding my 95' Lexus ES300 PYB 5w30 since i got the car about a year ago (first oil change was Penz plat)

My question is would a different oil help with MPG increase? or should i just keep feeding her PYB? (136k on clock)

95% of all my driving is city and stop and go. Out of a tank i can see anywhere from 16-18mpg.

Plugs, PCV, and fuel filter was done about a year ago. Air filter about 6 months ago.

If your daily trips are less than 10 miles, the oil almost never get to operating temperature of 200-210F, then you could use xW20. xW20 at 180-190F is as thick as xW30 at 200-210F and much thicker than xW30 at 220-230F.


HTSS-TR...If xw20 is the same Vis. at 180-190F as xw30 at 200-210F than what benefit would it be to use 5w20 for short tripping?

Not to mention I am confused that a 20wgt oil would be MUCH thicker than a 30wgt at 230F. Can you explain? I am now lost.
 
95-99% of good fuel economy is directly related to driving style.

Visit ecomodder.com or cleanmpg.com and find out some tips and tricks that work.
 
Originally Posted By: dtt004

I personally think you should not deviate any lower from that specification. You can always go higher than the specified (in viscosity), but you should never go lower. Reason being is that, the lower the viscosity, the less film strength that you get at higher operating temperatures.


This gets thrown around constantly on this forum, but I simply don't understand it. Film strength is hardly the only consideration when it comes to motor oil's function in an internal combustion engine. Using thicker oil than specified is just as likely to cause problems as using a thinner oil (if not more so), by increasing operating temperatures, engine seal friction, oil seal pressure, higher drag on the oil pump... Film strength is ONE consideration--and keep in mind that a thicker oil doesn't even necessarily have higher film strength, depending on bearing clearances.

I'd use the specified oil, or if the oil was rarely brought up to operating temperature I'd consider a thinner oil (or the thinnest oil that meets the specifications).

To your point about it not really mattering much for fuel economy, I agree completely. Yeah, it'll make a difference at a macro level, tens of thousands of cars saving a tiny percentage--but on an individual level small increases in engine efficiency are going to make for very tiny gains in fuel economy; small enough that I don't think I'd ever consider fuel economy a criteria for selecting an oil.
 
Originally Posted By: Smokescreen
95-99% of good fuel economy is directly related to driving style.

Visit ecomodder.com or cleanmpg.com and find out some tips and tricks that work.



And the fuel thats used. pure gas will give you better millage than the tainted garbage.
 
Originally Posted By: chubbs1
Originally Posted By: HTSS_TR
Originally Posted By: toofastgtp
I have been feeding my 95' Lexus ES300 PYB 5w30 since i got the car about a year ago (first oil change was Penz plat)

My question is would a different oil help with MPG increase? or should i just keep feeding her PYB? (136k on clock)

95% of all my driving is city and stop and go. Out of a tank i can see anywhere from 16-18mpg.

Plugs, PCV, and fuel filter was done about a year ago. Air filter about 6 months ago.

If your daily trips are less than 10 miles, the oil almost never get to operating temperature of 200-210F, then you could use xW20. xW20 at 180-190F is as thick as xW30 at 200-210F and much thicker than xW30 at 220-230F.


HTSS-TR...If xw20 is the same Vis. at 180-190F as xw30 at 200-210F than what benefit would it be to use 5w20 for short tripping?

Not to mention I am confused that a 20wgt oil would be MUCH thicker than a 30wgt at 230F. Can you explain? I am now lost.

If your daily trips are more than 20-30 miles, then at the end of the drives the oil temperature of xW30 could be around 200-210F. If the trips are less than 10 miles then the temp could be as low as 170-180F or even lower. At that low temp the oil much thicker than at 200-210F. If you use xW20 for short trips, then at 170-180F it is much thinner than xW30 but still thicker than xW30 at longer drives. Ideally, you want an oil that is as thin as possible from starting your engine until it reach normal operating temperature, and as thick as needed at operating temperature.

Using http://www.widman.biz/English/Calculators/Graph.html you will be able to see the oil thickness of various grades at various temp (in C). Then you'll see that for short drives you like to use as thin an oil as possible.
 
The approach I've always taken is to use the thinnest oil I can for a 100 mile drive in 85 degree weather. For me that's a 0w-30. That way I have the thinnest oil I can on short trips while still having the protection I need if I take a longer trip on the weekend.

If I put in a xw-20, I wouldn't be able to drive through the desert heat on the weekends without swapping my oil because I already worry about the 30 weight with it's 120 outside.
 
Originally Posted By: toyotapriusguy


If I put in a xw-20, I wouldn't be able to drive through the desert heat on the weekends without swapping my oil because I already worry about the 30 weight with it's 120 outside.


Hogwash. The Prius is DESIGNED to work with 0W20 in all temps.
 
Originally Posted By: toyotapriusguy
The approach I've always taken is to use the thinnest oil I can for a 100 mile drive in 85 degree weather. For me that's a 0w-30. That way I have the thinnest oil I can on short trips while still having the protection I need if I take a longer trip on the weekend.

If I put in a xw-20, I wouldn't be able to drive through the desert heat on the weekends without swapping my oil because I already worry about the 30 weight with it's 120 outside.


you gotta be nuts using 0w30 in a prius spec'd for 0w20.
 
I've got 5w-20 in my car that specs 5w-30 right now because it sees almost nothing but short trips. It hasn't exploded yet.

Also - let's keep in mind there's very little difference between a 5w-20 and 5w-30 energy conserving oil.

So yeah, oil weight might make the slightest, itty-bittiest difference you could imagine.

Originally Posted By: toyotapriusguy

If I put in a xw-20, I wouldn't be able to drive through the desert heat on the weekends without swapping my oil because I already worry about the 30 weight with it's 120 outside.


I LOL'd
 
Most all oils today are fuel efficient so there will be minimal difference in like viscosities. drop the viscosity and maybe a .01 or so mpg at the best.
 
Originally Posted By: JeremyInMT
Originally Posted By: toyotapriusguy
The approach I've always taken is to use the thinnest oil I can for a 100 mile drive in 85 degree weather. For me that's a 0w-30. That way I have the thinnest oil I can on short trips while still having the protection I need if I take a longer trip on the weekend.

If I put in a xw-20, I wouldn't be able to drive through the desert heat on the weekends without swapping my oil because I already worry about the 30 weight with it's 120 outside.


you gotta be nuts using 0w30 in a prius spec'd for 0w20.


Yeah having a oil that's a couple cSt higher than recommended is a absolute crime...
crackmeup2.gif
 
Originally Posted By: JeremyInMT
Originally Posted By: toyotapriusguy
The approach I've always taken is to use the thinnest oil I can for a 100 mile drive in 85 degree weather. For me that's a 0w-30. That way I have the thinnest oil I can on short trips while still having the protection I need if I take a longer trip on the weekend.

If I put in a xw-20, I wouldn't be able to drive through the desert heat on the weekends without swapping my oil because I already worry about the 30 weight with it's 120 outside.


you gotta be nuts using 0w30 in a prius spec'd for 0w20.


Are you serious? Nothing "nutty" about it at all, Prius's up until 2009 were specified to run xW30 as the preferred grade. Very sensible of toyotapriusguy to not go thinner than recommended with desert temperatures up to 120 degrees.
 
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Originally Posted By: uart
Originally Posted By: JeremyInMT
Originally Posted By: toyotapriusguy
The approach I've always taken is to use the thinnest oil I can for a 100 mile drive in 85 degree weather. For me that's a 0w-30. That way I have the thinnest oil I can on short trips while still having the protection I need if I take a longer trip on the weekend.

If I put in a xw-20, I wouldn't be able to drive through the desert heat on the weekends without swapping my oil because I already worry about the 30 weight with it's 120 outside.


you gotta be nuts using 0w30 in a prius spec'd for 0w20.


Are you serious? Nothing "nutty" about it at all, Prius's up until 2009 were specified to run xW30 as the preferred grade. Very sensible of toyotapriusguy to not go thinner than recommended with desert temperatures up to 120 degrees.



Exactly. While Your all busy tearing into someone, turns out Your wrong.

MY car is spec'ed for 5w-30. It has the 1.5l, not the 1.8l which is spec'ed for Xw-20

Toyota has said it's ok to use 5w-20 in certain situations, but I doubt they meant my driving technique, and even if they did I doubt any of You follow Your owners manual.
 
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So i will keep it PYB then.

Also, E10 vs 100% gas believe it or not i get better gas mileage with Shell E10 vs Philips "real" gas.
 
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