Oil Weights and use?

[Handyfarmer]

question,

I basically was given a 1995 suzuki swift, (Chevy Geo), it has about 65,000 miles,

I had a surging problem when warm and idling, I was able to by pass the high idle system and solve the problem,

but in reading about the car, some one on one of the forums said they were using 0-30 wt oil in there car, and getting 50 miles to the gallon,

I was able to get a Mile to gallon test a few days ago, and got 39.09 miles per gallon,

I want to change the oil I am guessing it has the recommended oil in it the 5-30 , oil in it, but not sure,

would 0-30 cause any problems? If I chose to try it, (I never like the idea of 0 wt oil,

any thoughts?

 

[exranger06]

A Suzuki Swift will get 50 mpg no matter what oil you use in it. A 0w-30 oil is not a "0 weight" oil, it's 30 weight. 5w30 and 10w30 are also 30 weight oils. The important number is the second number (30). That's the thickness of the oil at operating temp. So 0w30 is the SAME thickness as 5w30 at operating temp. The first number just tells you how much the oil thickens up in freezing temps. The higher the number, the more it's going to thicken up (which is a bad thing). So a 0w30 will flow better in freezing temps and that's about it. But it's safe to use in pretty much any engine that requires a 5w30 or 10w30 oil.

 

[MattT]

exranger pretty much covered it If the guy saw an improvement in mileage it was probably due to switching from dino to synthetic. Or possibly short trips where the oil doesn't get up to operating temperature.

 

[finn]

Exactly. A 0w oil will flow better cold, which means it takes less horsepower to turn the oil pump, which means, in turn, that less fuel is burned.

After the engine reaches operating temperature, both oils in question have the same viscosity, so pump work is the same. Short trips mean more time, relatively, spent warming up the engine, where the viscosity and pumping work is higher with a given oil.

 

[nadogail]

If I recall correctly, the first number is an indicator of the viscosity when it is cold. 5 weight oil cold is thicker then 30 weight hot, the difference between the 5 cold and 30 hot is because a viscosity index improver has been added to the 5 weight oil. The second number is the equivalent viscosity when hot.

My memory may be clouded because I was taught this during the middle 1950's.

 

[matt_i]

My info is that multi grade pure petroleum additives eventually push the weight towards the first number as the additive package "wears down" and becomes less effective.

But, with the advent of synthetic oils, these are fabulously better than what was available even 20 years ago. So I would trust the "multi grade" viscosity to maintain far longer than a pure dino-oil.

 

[sberry]

I agree it's better, in the real world there is some wiggle room.and it all gets better. Dino is already 2 generations better than when the car was made. If the engine is tight, not a fouling problem and doesn't have an inherent flaw common Dino oil is good north of 30k in a modern car.
I don't really try to outhink it, use the listed.oil unless there is a real compelling reason to change the type.

 

[SeisMec]

I had a surging problem when warm and idling, I was able to by pass the high idle system and solve the problem,
...
I was able to get a Mile to gallon test a few days ago, and got 39.09 miles per gallon

If you live in the northern third of the lower 48, the 0-30 should help with engine longevity. If you do mostly all short trips – 10 miles or less, you might see a very slight but measurable gain in average MPG. Say 0.5 to 1.0 mpg MAX.

*******

The surge may have been a problem for you, but you should think of it as a symptom. When you by-passed the high idle system, you eliminated the symptom. But you probably didn't cure the problem - which is the likely cause of your poor fuel economy.

 

[bczygan]

Use what your owners manual says to use.

Bill

 

[ddawg16]

The W stands for Winter....hence '5Winter30@temp'

A lot of people think the W meant 'weight'

 

[SGKent]

oil questions should be delegated to somewhere between your conscience and the owner's manual. What oil do you use questions usually end up as 700 pages of arguments.

 

[JohnnieMo]

My dad was a big believer in using 0W oil in GM products in the 80's and 90's. We lived in Saskatchewan where the winter temps were extremely cold and the 0W oil helped the cars start in that cold. It never damaged the engines and in fact, the 1991 Lumina I had lasted 426,000km.

All I'm saying is GM engines of that era could handle the 0W oil in the cold. Not sure who built the engine in your rig though. Of course, as others said, if it ain't cold, then what's the point?

 

[Stadger]

oil questions should be delegated to somewhere between your conscience and the owner's manual. What oil do you use questions usually end up as 700 pages of arguments.

Amen, it's a troll question.

 

[finn]

Amen, it's a troll question.

I agree, but in this case, I don’t really see anybody arguing.

Consensus seems to be use what the manufacturer recommends and get on with life.

Quite extraordinary for an Internet forum, actually.

 

[Handyfarmer]

Thank you all for your input, I will put the manual recommended oil in the car,

 

[rburke65]

I never knew the W meant winter...

 

[theoldwizard1]

My dad was a big believer in using 0W oil in GM products in the 80's and 90's. We lived in Saskatchewan where the winter temps were extremely cold and the 0W oil helped the cars start in that cold.

That's a GOOD place to use 0W-30 !

Tip for those who live in cold climates and use small engines. If the temp is going to routinely go down to 0F, switch to 0W30 or even 0W20, at least for winter. The engine will start easier and run better.

 

[JohnnieMo]

That's a GOOD place to use 0W-30 !

Tip for those who live in cold climates and use small engines. If the temp is going to routinely go down to 0F, switch to 0W30 or even 0W20, at least for winter. The engine will start easier and run better.

I used to start my 1991 Chev Lumina (3.1 V6) in about -35C without the block heater. It never had an issue. I credit that to the oil. That car ran 436,000km until I put some 20W50 in it and blew the engine one summer. What an idiot...

 

[redmondjp]

I used to start my 1991 Chev Lumina (3.1 V6) in about -35C without the block heater. It never had an issue. I credit that to the oil. That car ran 436,000km until I put some 20W50 in it and blew the engine one summer. What an idiot...

At that mileage, I really doubt that the oil weight had anything to do with your engine failure.

I've been experimenting with non-specified lubricants myself now for several years, so far with good results. For one example, I now run 15w-40 diesel oil in my small engines and garden tractors, with excellent results. I only share my own experiences, making no recommendations to others.

 

[swamplife]

I generally use whichever oil I can buy cheap!

It's interesting how some engines prefer it one way or another. I had a Focus with the 2.0 duratec/mzr and it seemed to prefer 0w-20. Whisper quiet on it. I tried running 10w30 in it once and it did not like it, very noisey.

My Subaru forester (FB25 engine) is not a fan of 0w-20. Very noisey and rattley. Probably some sort of exhaust resonance. But I bought a bunch of 0w-40 for $1/qt a while back and the engine seems to love it! However, for warranty purposes, it has the correct oil on the receipts.