Thinnest oil in 4g63 for fuel efficiency

[4gfun]

My 6 bolt 93 DSM will be used for horribly long highway commutes and I anticipate that it will remain very close to stock.

I've been playing around with oils in all types of vehicles to get the best possible fuel economy and since this will be essentially a stock daily, I'd like to see how thin I can go.

I have done ALOT of research on this topic. I have hit bobistheoilguy in the past as well but want to see what you'd like to say about it here.

I have gotten VERY aggressive with engines that were never designed to run thin oils or long oil change intervals. Example: 1993 Ford Escort GT (Mazda BP). I ran 0w-20 with 15k Oil Change Intervals (of course extended life oil filters were used). I have never had any problems....but I didn't care much about the vehicles.

My conclusion is that this engine really won't do well with anything thinner than a 10w-30. Just don't come in here telling me that this platform cannot be made VERY fuel efficient for what it is because that is not the case.

Thanks!

 

[JusMX141]

Never use thinner than 10W30 in these engines unless you live in a climate that never exceeds 60*f.

Our cars were built in an era when "efficiency" oils didn't exist. Using a 0W20 in a DSM would result in low oil pressure, bearing damage, and seal leakage.

 

[4gfun]

Never use thinner than 10W30 in these engines unless you live in a climate that never exceeds 60*f.

Our cars were built in an era when "efficiency" oils didn't exist. Using a 0W20 in a DSM would result in low oil pressure, bearing damage, and seal leakage.

Well that settles it for me coming from you. I'll save the rest of my FE game for the drivetrain fluids and by adjusting my driving habits along with ECU tuning. Much appreciated.

Thank you

 

[zedicus]

you can use synthetics and a micro lube additive. it actually helps noticeable.

i know i know " an oil additive are you an idiot?!?" it does not advertise as some 100% power increasing magic mystery fluid. it is plain and simply an ultra light weight oil that is safe to mix with your regular oil. think of it as being able to run 2 different weights to lube at 2 different efficiency.

z-max
marvel mystery i think has one
lucas oils has one.

they are kind of hard to find because they are not marketed as magic engine repair in a bottle. walmart here does not carry any of them.


Z-max was actually sued over their product and won the court case because they were able to substantiate their claims.

 

[boost97gst]

If it were stock and you are monitoring oil pressure with a quality mechanical gauge i wouldnt be shy about trying a 5/30 synth in it.

My 06 lincoln takes 5/20(as do most newer Fords) I put 90% hwy miles on it. About 4k a month. I change it at roughly 4500 -5000 miles. I could go way longer im sure but its not worth the risk. That said, its totally irrelevant: a 3.9Lv8 is NOT the 4g63.

It really depends on the clearances and condition of your engine and what hot idle pressure looks like. Try 5 30 and if its a stock, DD car that you dont beat on, maybe even go down to 5 20.

 

[Primecut4ya]

I would have to say that once at operating temp there is not going to be much if any difference in a 5/30 or 10/30. My attention would be more towards proper tire inflation and style, good plugs and wires,clean fuel system, clean air filter your acceleration, MPH, and where you are purchasing your fuel. All of these while have more to contribute to gas mileage then an oil..

 

[WES_393]

I would have to say that once at operating temp there is not going to be much if any difference in a 5/30 or 10/30. My attention would be more towards proper tire inflation and style, good plugs and wires,clean fuel system, clean air filter your acceleration, MPH, and where you are purchasing your fuel. All of these while have more to contribute to gas mileage then an oil..

/thread

Seriously though, there's dozens of ways to improve mileage that don't involve risking your engine. The biggest one being your right foot.

 

[Tyeler18]

Can't use anything less than 10w-30? These cars were built in an age where efficiency wasn't a high claim, however, the oils of the time were just as lowly as the mileage ratings. Oils have come a long ways since 1990 and honestly a 10w-30 back then would be blown out of the water by a 0w-20 now due to the additives present in new oils.

There are a few things to note. Like mentioned above, a 5w-30 vs a 10w-30 are only different when cold. This is the whole point behind multi-viscosity oils. They will perform and lube at identical spectrums when warm hence the "30." Cold starts are the only worry, but to be honest, if you live anywhere it ever gets below freezing, a 5weight will do your bearings much BETTER than a 10.

I've personally used 5w-30 in multiple of my dsms for thousands of miles. Having pulled a few of the engines aparts I can say with firm assurance, there was no bearing damage from it. Something else to note, however, is that I didn't see any confirmable increase in MPG, which would make sense considering the viscosity is only different when cold, which is very little time driving.

I have logged over 44mpg out of my near bone stock 98 gst spyder on multiple occasions. With normal driving I average a consistent 26mpg, 100% in town driving. I drive like an average person does, in boost to some degree. This is a 120k gst spyder, 5 speed, with a K&n open air filter as the only mod. Still utilizing stock fuel and timing maps. I've pulled 44mpg out of it driving through the rockies with it loaded down with over 600lbs worth of crap (I was moving).

Take note ^^ was done on a FWD. Don't expect the same out of an AWD. BUT on the same trip through the rockies, again loaded down with well over 600lbs/each- my bone stock (bone stock) GVR4 pulled a steady 34mpg spooling 10lbs of boost for a good majority of the trip, and my mildly modded 90 AWD talon managed 36mpg. Both were also on stock fuel maps/timing.

I'd highly suggest investing in a tuning source and a wideband for the largest improvement in MPG. Obviously the less you're in boost the better, however, lugging down the engine to stay out of boost can result in higher fuel consumption than allowing the engine to power to speed. Proper RPM and engine load are the keys to the best mileage.

 

[4gfun]

Can't use anything less than 10w-30? These cars were built in an age where efficiency wasn't a high claim, however, the oils of the time were just as lowly as the mileage ratings. Oils have come a long ways since 1990 and honestly a 10w-30 back then would be blown out of the water by a 0w-20 now due to the additives present in new oils.

There are a few things to note. Like mentioned above, a 5w-30 vs a 10w-30 are only different when cold. This is the whole point behind multi-viscosity oils. They will perform and lube at identical spectrums when warm hence the "30." Cold starts are the only worry, but to be honest, if you live anywhere it ever gets below freezing, a 5weight will do your bearings much BETTER than a 10.

I've personally used 5w-30 in multiple of my dsms for thousands of miles. Having pulled a few of the engines aparts I can say with firm assurance, there was no bearing damage from it. Something else to note, however, is that I didn't see any confirmable increase in MPG, which would make sense considering the viscosity is only different when cold, which is very little time driving.

I have logged over 44mpg out of my near bone stock 98 gst spyder on multiple occasions. With normal driving I average a consistent 26mpg, 100% in town driving. I drive like an average person does, in boost to some degree. This is a 120k gst spyder, 5 speed, with a K&n open air filter as the only mod. Still utilizing stock fuel and timing maps. I've pulled 44mpg out of it driving through the rockies with it loaded down with over 600lbs worth of crap (I was moving).

Take note ^^ was done on a FWD. Don't expect the same out of an AWD. BUT on the same trip through the rockies, again loaded down with well over 600lbs/each- my bone stock (bone stock) GVR4 pulled a steady 34mpg spooling 10lbs of boost for a good majority of the trip, and my mildly modded 90 AWD talon managed 36mpg. Both were also on stock fuel maps/timing.

I'd highly suggest investing in a tuning source and a wideband for the largest improvement in MPG. Obviously the less you're in boost the better, however, lugging down the engine to stay out of boost can result in higher fuel consumption than allowing the engine to power to speed. Proper RPM and engine load are the keys to the best mileage.

These were my thoughts when I started the thread. The Escort GT (mazda 1.8 BP) was not designed for 0w-20 oil either but I never had any issue with it.

What worries me more than anything is whether or not the turbo can handle that thin oil.

BTW, I am curious as to how you got 34 MPG out of your GVR4....but not nearly as curious as to why I can't. I get 21 mpg driving like a madman and 22 mpg driving 58 mph with 95% highway miles. Tires are inflated properly, vehicle is aligned properly, and I am running 18.1:1 after tuning it that way off boost. (Also verified with a WBO2). During that run, I didn't get into boost even once.

My only thoughts are: front bumper cut open for flow to intercooler and hood vents. There is no way that stuff could account for such crappy mileage. Perhaps the 180 Thermo is doing it?

 

[WES_393]

What worries me more than anything is whether or not the turbo can handle that thin oil.

The viscosity isn't so much of an issue as the lack of additives. These cars were built in a time when Uncle Sam had very little concern over what came out your tailpipe. Today, there's barely enough ZDDP in standard oils to keep a journal bearing turbo happy, let alone in a Eco-Friendly 0w20. I would look into Eneos, Mitsubishi's own blend of oil.

http://www.streettunedmotorsports.com/parts/eneos_oil.htm

 

[4gfun]

The viscosity isn't so much of an issue as the lack of additives. These cars were built in a time when Uncle Sam had very little concern over what came out your tailpipe. Today, there's barely enough ZDDP in standard oils to keep a journal bearing turbo happy, let alone in a Eco-Friendly 0w20. I would look into Eneos, Mitsubishi's own blend of oil.

ENEOS NIPPON MOTOR OIL

Thanks for this explanation.

 

[Tyeler18]

BTW, I am curious as to how you got 34 MPG out of your GVR4....but not nearly as curious as to why I can't. I get 21 mpg driving like a madman and 22 mpg driving 58 mph with 95% highway miles. Tires are inflated properly, vehicle is aligned properly, and I am running 18.1:1 after tuning it that way off boost. (Also verified with a WBO2). During that run, I didn't get into boost even once.

My only thoughts are: front bumper cut open for flow to intercooler and hood vents. There is no way that stuff could account for such crappy mileage. Perhaps the 180 Thermo is doing it?

Good question honestly. My engine had 130psi of compression at 8000ft (should be more now that I'm at 1600ft. It's bone stock, so I can't do much for logging on it. I daily it and pull an easy 25mpg. A few things to note- 185k, it's NOT properly aligned currently, I have all seasons on it at 34lbs/corner, a few boost leaks that are minor in size, the valve seals leak bad enough right now that I go through about a quart of oil every 500-1000 miles depending on how hard I'm driving it, and it has a few HUGE exhaust leaks from the factory downpipe back. Runs like a top though. I try and shift around 3000, however, a 3500lb car on a 185k engine doesn't move out of its way very easily without boost, so I do have to get on it at times to get out into traffic.

I try to limit the amount of time spent in boost unless absolutely necessary. Balancing the load against the RPM is the biggest thing. Lots of people will say to just lug it out of boost until your up to speed, but when you're creeping at 2k trying to get up to speed you're actually using more fuel than say a few lbs of boost for a short burst.

 

[DSM1G90]

Tires at 32psi, oil - either dino or synth at 10w30 regularly changed and you can muster decent mileage with that motor.

I'm a turbo DD and I can hit 26mpg doing 70mph on the freeway with the oil weight that I posted driving 30 miles from home to work and back.

If I do sustained, 300 mile (full tank fill) freeway driving with cruise on at 80mph without stopping, I can almost hit 30mpg.

And I'm full stock with an added catch can.

-DSM

 

[pneumo]

I tried different weight oils to see if they improved FE when I had a long commute. I saw a slight difference, maybe 1mpg at best. I also noticed when the oil was too thin I could feel an extra vibration when lugging it. It felt like the bearings were making contact. I later swapped out the bearings and the odd vibration went away. The old bearings still looked good, they had even wear but they did have some wear. Oil pressure also improved with the new bearings.

I also like to change oil according to the season. Just like it says in the owners manual, use thicker oil in summer, thinner oil in winter.

 

[4gfun]

Good question honestly. My engine had 130psi of compression at 8000ft (should be more now that I'm at 1600ft. It's bone stock, so I can't do much for logging on it. I daily it and pull an easy 25mpg. A few things to note- 185k, it's NOT properly aligned currently, I have all seasons on it at 34lbs/corner, a few boost leaks that are minor in size, the valve seals leak bad enough right now that I go through about a quart of oil every 500-1000 miles depending on how hard I'm driving it, and it has a few HUGE exhaust leaks from the factory downpipe back. Runs like a top though. I try and shift around 3000, however, a 3500lb car on a 185k engine doesn't move out of its way very easily without boost, so I do have to get on it at times to get out into traffic.

I try to limit the amount of time spent in boost unless absolutely necessary. Balancing the load against the RPM is the biggest thing. Lots of people will say to just lug it out of boost until your up to speed, but when you're creeping at 2k trying to get up to speed you're actually using more fuel than say a few lbs of boost for a short burst.

Thanks for the info. Compression is 160-164 in all cylinders and engine has just under 60k here. Looks like you have been blessed. Come to think of it, I am running 15w-50 and HeavyWeight Shockproof. Still...

 

[4gfun]

I tried different weight oils to see if they improved FE when I had a long commute. I saw a slight difference, maybe 1mpg at best. I also noticed when the oil was too thin I could feel an extra vibration when lugging it. It felt like the bearings were making contact. I later swapped out the bearings and the odd vibration went away. The old bearings still looked good, they had even wear but they did have some wear. Oil pressure also improved with the new bearings.

I also like to change oil according to the season. Just like it says in the owners manual, use thicker oil in summer, thinner oil in winter.

Yes, I remember your situation and I know that you are the master of this question but don't like to drag you into stuff unless I have to. I didn't know about the 1 mpg margin though! Thanks again.

 

[4gfun]

Tires at 32psi, oil - either dino or synth at 10w30 regularly changed and you can muster decent mileage with that motor.

I'm a turbo DD and I can hit 26mpg doing 70mph on the freeway with the oil weight that I posted driving 30 miles from home to work and back.

If I do sustained, 300 mile (full tank fill) freeway driving with cruise on at 80mph without stopping, I can almost hit 30mpg.

And I'm full stock with an added catch can.

-DSM

Great data, and now that I have a useable margin, it doesn't seem to make any sense at all to go any thinner than 10w-30.

 

[Tyeler18]

Thanks for the info. Compression is 160-164 in all cylinders and engine has just under 60k here. Looks like you have been blessed. Come to think of it, I am running 15w-50 and HeavyWeight Shockproof. Still...

All of mine now run either 15w-40 rotella or 5w-40 T6 and still maintain the same mileage. My 1g runs heavy duty shock proof in the tcase and rear end as well, and MT-90 in the trans. Definitely not ideal for the max MPG, but like I and Pneumo stated, the viscosity doesn't effect mileage all that much.

 

[4gfun]

All of mine now run either 15w-40 rotella or 5w-40 T6 and still maintain the same mileage. My 1g runs heavy duty shock proof in the tcase and rear end as well, and MT-90 in the trans. Definitely not ideal for the max MPG, but like I and Pneumo stated, the viscosity doesn't effect mileage all that much.

Very interesting. Great data though. I'd rather have your numbers though.

Same fluid setup as you. T-Case and Rearend running Heavyweight. Transmission running MT-90/MTL cocktail. I guess that what my GVR4 does is not that important since I am building the DSM for gas mileage...still curious though.

 

[Tyeler18]

Very interesting. Great data though. I'd rather have your numbers though.

I'm working on getting my evo ecu in my galant. If people would quit selling me junk ecu's I'd be able to post a log of my daily commute to give a comparison off of. I've been through 3 ecu's so far, all of which have been garbage.

 

[JusMX141]

Oils have come a long ways since 1990 and honestly a 10w-30 back then would be blown out of the water by a 0w-20 now due to the additives present in new oils.

Contrarily, today's oil couldn't be any shittier. It's to the point where the racing oils that many of us use contain simple additive packages that were used in every oil back in 1990....you'll even find many folks using CI-4 15W40 diesel oil as a poor-man's racing oil as it still contains the zinc and phosphorus that were in all oils when our engines were designed and built.

Multi-vis tech and perhaps temperature stabilization have improved thanks to synthetics, but just about every other aspect went out the window. Modern oils are lower-detergent because today's engines are supposed to be cleaner-running thanks to advancements in EGR and catalytic converter tech....the result is horrendous sludge issues when changed at standard service intervals in certain engines which require a higher-detergent oil of old.

There are a few things to note. Like mentioned above, a 5w-30 vs a 10w-30 are only different when cold. This is the whole point behind multi-viscosity oils. They will perform and lube at identical spectrums when warm hence the "30." Cold starts are the only worry...

While 5W30 and 10W30 share the same primary weight number, the 5W30 contains more viscosity index additives. These additives which are designed to make the oil flow better at colder temperatures will, in fact, cause the oil to break down quicker....especially if the oil sees very high temperatures as found in a high-performance turbocharged application.

If 5W30 and 10W30 were truly no different, then Mitsubishi would recommend 5W30 all the time.....buuuut they don't.

 

[lasershark]

Contrarily, today's oil couldn't be any shittier.....

If 5W30 and 10W30 were truly no different, then Mitsubishi would recommend 5W30 all the time.....buuuut they don't.

I agree the engineers kinda know what they are talking about, Ive seen some engine tests to see what it takes to kill one it's pretty crazy, oil is pretty much the blood of the engine I wouldn't risk an engine to try to save some pocket change in gas

just my thoughts though

 

[knochgoon24]

Before I knew better, I put 5w-20 full synthetic in my car. It was bone stock. It was low at first, but within a week, it dropped low enough that my oil pressure light would flicker at idle. I drained it and put 10w-30 back in. I would see 3-5 psi of oil pressure at a 750rpm hot idle.

 

[DSM1G90]

Our 2007 KIA Rondo uses the 5/20 since it's a pretty tight motor and uses the thin oil real good due to its tight tolerances.

But, that stuff is pretty thin coming out of the bottle...

 

[92nolatist]

My engine is fully built and tuned by myself and I run rotella 15w-40, and the highest mpg I've gotten to date was driving my awd talon to the 20th dsm shootout. Straight highway from jersey to Ohio and I averaged 30 mpg at 75-80 mph..... So in my opinion, oil viscosity doesn't matter as far as fuel efficiency goes. Just something to think about.

Edit. Around town and beating on her a little, I'll get from 20-22 with the 15w-40