Over thinking engine oil - MPG related

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For some reason i always
crackmeup2.gif
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.

First off, the car you're driving is pretty much maxed out, as far as fuel economy is concerned (Lets not count the fact that an auto manufacturer will detune an engine to produce worse gas mileage, while still better then the previous model year, because lets face it, if they give you the best they can do today, it will be hard for them to beat that tomorrow when the next model is introduced - but that's a whole other subject better left for tomorrow's conversation)

The engine in your car was designed for a certain MPG range in mind and the oil viscosity the auto maker choose best suits the lubrication the engine requires so metals don't fuse together.

Although i agree that using a lighter viscosity oil "can" result in a percent or two increase in gas mileage, the thought of increased engine wear in the long run seems to outweigh the benefits to me. A worn engine performs worse which results in less power produced which results in you need to push the gas pedal deeper into the carper just to accelerate as fast as the car did when the engine was "fresh"

^this sort of defeats the whole purpose of you trying to get better gas mileage IN THE LONG RUN, over the course of the life of your car.

Sure, some say that regardless, the car will fall apart waaaay before the engine decides to clock out from its shift, it still raises the question - are YOU the owner REALLY benefiting from the supposed "1-2% gas mileage increase" over the course of say a 5 year period of owning the car and racking up say, 100,000 miles with enough savings in gas mileage to make this practice actually "worth it"??? (not talking about a few dollars)


If you insist on trying to "squeeze" a few extra MPGs from your automobile, there are "civilized", common sense ways of doing so, starting with the duffus sitting in between the drivers seat and the steering wheel... (how you drive!)

Next you have properly inflated tires (or a few PSI more to decrease the rolling resistance), a clean engine air filter and basically a properly functioning engine is general.

Next you have the removal of excess weight (take out that pile of [censored] from the trunk!)

Something as simple as keeping the exterior of your car clean and Waxed is said to decrease the wind drag and help the air hitting the car "slip by" easier which helps RESTORE lost gas mileage vs driving with bird poo, leafs, branches and an inch of dust that has settled on your paint, causing excess drag (i've tested this one personally using a scan-gauge and driving with a dirty car vs clean & waxed)

I can go on for a few pages worth but there are LOADS of websites that list all the various things you can do (common sense things) to restore lost MPGs and add up to 5-10%+ with everything combined, all while still providing your engine with the required lubrication it so desperately needs.

I use a scan-gauge and am able to achieve much higher gas mileage then the highest average number posted on the window spec sheet that came on the cars i own. The tool has paid for itself 2-3 times over by helping me to adjust my driving style to increase my average fuel economy without having to result to the use of thinner oil and this happens with each and every tank full with receipts and gas mileage calculations increases much higher then 1%
33.gif


Thoughts?
35.gif
 
I am ready to SEE it. Where do lighter wgt. oils cause more wear?? Is it another conspiracy to get your car to to fall apart so you buy sooner? I think they have tested lighter oils quite a bit and if it is recommended for your car, use it.

Very few people use 0w20 when their car calls for 5w30. Am I missing something?
 
Originally Posted By: Artem

The engine in your car was designed for a certain MPG range in mind and the oil viscosity the auto maker choose best suits the lubrication the engine requires so metals don't fuse together.



This thread will probably end in another thick vs thin war and get locked but here goes. I agree with just about everything you've written. The line above in quotes hit the mark. Why do people insist that if a car maker states using a 20 grade oil, that it is not good, and all about CAFE? Then mention that in other parts of the world where a 20 grade oil is not as easily available that there is some consipracy by the US gov't and car makers to destroy these engines used in America early? I'm certain the engines calling for thinner oils have been extensively tested and are doing fine. If owned a new car that called for a 30 grade oil that's what I'd use, even if another vehicle of mine which might be older calls for a 20 grade oil. Since I didn't design and build the engine I'll leave the oil choice up to the engine builder and company that is guaranteeing the engine. If given a choice of oil, I'll match it up to the kind of use the vehicle sees and the temps it will be used in. No choices given I'll use what the fill cap says. Getting an extra 5 miles out of a tank of gas means nothing to me.

JMO
 
Originally Posted By: chubbs1
I am ready to SEE it. Where do lighter wgt. oils cause more wear?? Is it another conspiracy to get your car to to fall apart so you buy sooner? I think they have tested lighter oils quite a bit and if it is recommended for your car, use it.

Very few people use 0w20 when their car calls for 5w30. Am I missing something?


+1
 
Originally Posted By: chubbs1
Very few people use 0w20 when their car calls for 5w30. Am I missing something?
I think that's what the OP is getting it.

Using oil that is weighted "below" what the manufacturer has rated for that engine, could be detrimental to both performance, and the longevity of the engine.

Now don't get me wrong, If there was some 5W-20 laying around the garage, I wouldn't heistate to use it as top-off oil in a vehicle spec'ing 5-30 or 10-30....
 
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!
 
It's ego but many think they "need" thicker because of some aggressive driving, uncomfortable (for humans) heat, or a ditsy spouse being hard on the engine.

But every engine endures cold starts. Even taxis get a couple a day.

By upping the "protection" for the extremes, which you rarely encounter anyway, you are shortchanging your engine on start up wear, which happens EVERY TIME and is documented in study after study.

OP, have you installed a pressure and or oil temperature gauge? Have you run a 20 weight and seen dangerous results?
 
Originally Posted By: chubbs1
I am ready to SEE it. Where do lighter wgt. oils cause more wear?? Is it another conspiracy to get your car to to fall apart so you buy sooner? I think they have tested lighter oils quite a bit and if it is recommended for your car, use it.

Very few people use 0w20 when their car calls for 5w30. Am I missing something?


I'm not talking about engines which spec a thin oil from the factory.

I'm talking about using a 5w20 which your engine specs 5w30. (not going to get into the 0w topic because we all know that good and well by now and there are active threads on that topic)

Also, if you're willing to wait 5-10 years while i run a 5w20 in an engine spec'd for 5w30 and then disassemble the block and look for excess wear vs the same engine which ran on 5w30 i'd be glad to do so.
 
Whats interesting is automakers sometimes spec say 0w20 like in the prius in japan and usa but in europe may quote 5w30.. if it was a cafe issue i would suspect they wouldnt use it in japan? or do they have simular laws?
 
Originally Posted By: demarpaint
Originally Posted By: Artem

The engine in your car was designed for a certain MPG range in mind and the oil viscosity the auto maker choose best suits the lubrication the engine requires so metals don't fuse together.



This thread will probably end in another thick vs thin war and get locked but here goes. I agree with just about everything you've written. The line above in quotes hit the mark. Why do people insist that if a car maker states using a 20 grade oil, that it is not good, and all about CAFE? Then mention that in other parts of the world where a 20 grade oil is not as easily available that there is some consipracy by the US gov't and car makers to destroy these engines used in America early? I'm certain the engines calling for thinner oils have been extensively tested and are doing fine. If owned a new car that called for a 30 grade oil that's what I'd use, even if another vehicle of mine which might be older calls for a 20 grade oil. Since I didn't design and build the engine I'll leave the oil choice up to the engine builder and company that is guaranteeing the engine. If given a choice of oil, I'll match it up to the kind of use the vehicle sees and the temps it will be used in. No choices given I'll use what the fill cap says. Getting an extra 5 miles out of a tank of gas means nothing to me.

JMO



Again, if an engine was designed for 5w20 in mind, by all means, use it!

Its when i see the SAME engine which asked for 5w30 last year, now lists 5w20 this year that i begin to question what caused the change in viscosity besides trying to get an extra MPG or 2 on paper by the automaker.

I'm use over the years, engine durability tests have been performed long enough to know what's safe to use.

Seeing as with proper OCIs and maintenance an engine will keep running for a million miles, automakers know that the engine will be "fine" with a slightly thinner oil. It will outlast the car regardless.

The main point in this thread is the use of thinner oils in older cars simply to: INCREASE GAS MILEAGE by .0001%
 
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!


I'm not talking about engines which call for a thin oil from the factory.

Originally Posted By: eljefino
It's ego but many think they "need" thicker because of some aggressive driving, uncomfortable (for humans) heat, or a ditsy spouse being hard on the engine.

But every engine endures cold starts. Even taxis get a couple a day.

By upping the "protection" for the extremes, which you rarely encounter anyway, you are shortchanging your engine on start up wear, which happens EVERY TIME and is documented in study after study.

OP, have you installed a pressure and or oil temperature gauge? Have you run a 20 weight and seen dangerous results?


I'm working my way up to installing the two to have more data then that provided by the engine management system currently in the car.

I would not run a 20 grade in an engine asking for 30 to experiment with "dangerous results"

Originally Posted By: Dieseldoctor
Whats interesting is automakers sometimes spec say 0w20 like in the prius in japan and usa but in europe may quote 5w30.. if it was a cafe issue i would suspect they wouldnt use it in japan? or do they have simular laws?


I also find it extremely interesting why the same engine maker specs two very different oil viscosities in different countries.
 
Originally Posted By: eljefino
It's ego but many think they "need" thicker because of some aggressive driving, uncomfortable (for humans) heat, or a ditsy spouse being hard on the engine.



grin2.gif
why do i get the feeling this quote is closely related to my posts in my other threads?
lol.gif
 
I 100% agree with you. When I was shopping for my new commuter car last fall I had an option (theoretically) of buying a big SUV guzzling 15 MPG and then dilute the oil with solvents to bump the MPG to 16 MPG or buy Prius that gives me 55 MPG in city driving. Guess which route I went?

BTW, Prius uses 0W20 and I'm OK with that considering that engine is off a significant portion of my commute (downhill, coasting before red lights and waiting for green light).

So, for me this squeezing extra MPG from too big cars by thin oil is one huge DUH!

One more thing: how come the 18 wheelers are still using 15W40 and not 5W20?
 
Originally Posted By: Artem
For some reason i always
crackmeup2.gif
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.

First off, the car you're driving is pretty much maxed out, as far as fuel economy is concerned (Lets not count the fact that an auto manufacturer will detune an engine to produce worse gas mileage, while still better then the previous model year, because lets face it, if they give you the best they can do today, it will be hard for them to beat that tomorrow when the next model is introduced - but that's a whole other subject better left for tomorrow's conversation)

The engine in your car was designed for a certain MPG range in mind and the oil viscosity the auto maker choose best suits the lubrication the engine requires so metals don't fuse together.

Although i agree that using a lighter viscosity oil "can" result in a percent or two increase in gas mileage, the thought of increased engine wear in the long run seems to outweigh the benefits to me. A worn engine performs worse which results in less power produced which results in you need to push the gas pedal deeper into the carper just to accelerate as fast as the car did when the engine was "fresh"

^this sort of defeats the whole purpose of you trying to get better gas mileage IN THE LONG RUN, over the course of the life of your car.

Sure, some say that regardless, the car will fall apart waaaay before the engine decides to clock out from its shift, it still raises the question - are YOU the owner REALLY benefiting from the supposed "1-2% gas mileage increase" over the course of say a 5 year period of owning the car and racking up say, 100,000 miles with enough savings in gas mileage to make this practice actually "worth it"??? (not talking about a few dollars)


If you insist on trying to "squeeze" a few extra MPGs from your automobile, there are "civilized", common sense ways of doing so, starting with the duffus sitting in between the drivers seat and the steering wheel... (how you drive!)

Next you have properly inflated tires (or a few PSI more to decrease the rolling resistance), a clean engine air filter and basically a properly functioning engine is general.

Next you have the removal of excess weight (take out that pile of [censored] from the trunk!)

Something as simple as keeping the exterior of your car clean and Waxed is said to decrease the wind drag and help the air hitting the car "slip by" easier which helps RESTORE lost gas mileage vs driving with bird poo, leafs, branches and an inch of dust that has settled on your paint, causing excess drag (i've tested this one personally using a scan-gauge and driving with a dirty car vs clean & waxed)

I can go on for a few pages worth but there are LOADS of websites that list all the various things you can do (common sense things) to restore lost MPGs and add up to 5-10%+ with everything combined, all while still providing your engine with the required lubrication it so desperately needs.

I use a scan-gauge and am able to achieve much higher gas mileage then the highest average number posted on the window spec sheet that came on the cars i own. The tool has paid for itself 2-3 times over by helping me to adjust my driving style to increase my average fuel economy without having to result to the use of thinner oil and this happens with each and every tank full with receipts and gas mileage calculations increases much higher then 1%
33.gif


Thoughts?
35.gif



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.
 
Originally Posted By: eljefino
It's ego but many think they "need" thicker because of some aggressive driving, uncomfortable (for humans) heat, or a ditsy spouse being hard on the engine.

I occasionally race my cars at the drag strip so yes I'm "hard" on my stuff...

Originally Posted By: eljefino

But every engine endures cold starts. Even taxis get a couple a day.

By upping the "protection" for the extremes, which you rarely encounter anyway, you are shortchanging your engine on start up wear, which happens EVERY TIME and is documented in study after study.


So how is using 5W-30 or a 0W-40 causing more wear at start-up than a 5W-20???

Originally Posted By: eljefino

OP, have you installed a pressure and or oil temperature gauge? Have you run a 20 weight and seen dangerous results?


I dare say you could run WD40 in many engines and achieve minimum oil pressure specs, no doubt it isn't a good idea...
 
Nice choice on the Prius vs 10 MPG and $120 fill ups (if you're lucky)

The Prius specs 0w20 from the factory and i'd use the exact same thing if i had the car. No point in trying to "re-engineer" the proper oil grade for the engine when Toyota already did that.

Again, this thread is not about the use of thin oils in engines that spec them.
 
Originally Posted By: TFB1
Originally Posted By: eljefino
It's ego but many think they "need" thicker because of some aggressive driving, uncomfortable (for humans) heat, or a ditsy spouse being hard on the engine.

I occasionally race my cars at the drag strip so yes I'm "hard" on my stuff...

Originally Posted By: eljefino

But every engine endures cold starts. Even taxis get a couple a day.

By upping the "protection" for the extremes, which you rarely encounter anyway, you are shortchanging your engine on start up wear, which happens EVERY TIME and is documented in study after study.


So how is using 5W-30 or a 0W-40 causing more wear at start-up than a 5W-20???

Originally Posted By: eljefino

OP, have you installed a pressure and or oil temperature gauge? Have you run a 20 weight and seen dangerous results?


I dare say you could run WD40 in many engines and achieve minimum oil pressure specs, no doubt it isn't a good idea...



Yea i don't get how going from 5w30 to say 5w40 is causing more wear at start up considering both oils are 5w in the morning.

In my Civic Si which gets driven HARD DAILY! 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) (i'm still maintaining the 5w spec to keep wear down during cold start)
 
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