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Someone mentioned the muffler had some sort of valve to keep back pressure even between low and high rpms.

I cut my muffler off and welded on a plain piece of exhaust pipe. The OEM is a generic cheap $30 muffler with baffles, no valve.

Several people talked about the oil change meter claiming it can analyze remaining oil life. No, it's simply hooked up to the odometer. It might have a way to adjust for city vs highway miles, but I doubt it.

The Chevy Spark is a low end economy car made by Daewoo at a price point, not a Mercedes Benz or Lexus.

I don't want to ruffle anybody's feathers, but it's hard to believe no one was called out for this ridiculousness (until now).

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This is directly for the owners manual:

This vehicle has a computer system that indicates when to change the engine oil and filter. This is based on a combination of factors which

include engine revolutions, engine temperature, and miles driven. Based on driving conditions, the mileage at which an oil change is

indicated can vary considerably. For the oil life system to work properly, the system must be reset every time

the oil is changed.

Yes, you are right about miles between changes but it has other factors besides just miles.

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Well, just because they say it's so I'm going to be stubborn and not believe it. On my next oil change (about 2-3 months) I'll reset the oil change function. I change my oil every 5000 miles with full synthetic 5w30 SuperTech from Walmart (I don't believe the GM additive bull). I'll report back with the percentage left and then reset and go another 5000 miles with a fresh change.

I strongly suspect the second percentage is going to match the first exactly. If the parameters really include engine temp and revolutions, the percentage readings are going to have to be different.

This is going to take about 6 months, but we will have a definitive answer based on actual results, not on advertising/marketing hype.

Edited by gitsum
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Just looking it up.

The algorithm was developed over the course of many years by several lubrication experts at GM Fuels and Lubes, spearheaded by Doctor Shirley Schwartz who holds the patents (with GM) for the algorithm and the oil life montitor.

Look up Doctor Shirley Schwartz GM. The same oil monitor algorithm is use (bought) by many manufactures. So there you have it.

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Just looking it up.

The algorithm was developed over the course of many years by several lubrication experts at GM Fuels and Lubes, spearheaded by Doctor Shirley Schwartz who holds the patents (with GM) for the algorithm and the oil life montitor.

Look up Doctor Shirley Schwartz GM. The same oil monitor algorithm is use (bought) by many manufactures. So there you have it.

I really trust GM. The same company that says I need a GM brand oil with a "specific" additive or else risk engine damage.

The same people that denied there was an ignition switch/cylinder problem that caused engines to shut down. After enough people got killed or injured they finally decided to do a recall.

Must be a really sophisticated algorithm, a little extra rpm and heat will reduce the engine oil life. I'm really gonna trust that!

I'm going to put about 150k on this car before I retire it. Not following the "sophisticated" oil change algorithm is going to the best thing I ever did for the car.

I'm still going to post the oil life percentage results here.

Remember, the Spark is a Daewoo not a GM (thank goodness).

Edited by gitsum
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I reset the second trip meter to zero whenever the oil life monitor drops one %. The oil life monitor is checked almost each time I put the car in 'Park' so I can get an accurate idea of how many miles I drove between a one% drop. When I drive in cooler weather for very short trips, I get about 45mi per 1% drop. On longer trips when the engine is mostly driven at operating temp I get about 95mi per 1% drop. That's the math that shows the oil life monitor takes mileage, ambient, rpms & engine temp, etc readings to determine the distances between a 1% drop. It does not do any form of actual oil chemical quality analysis but it does take the above parameters into consideration to calculate what the oil condition should be given the activity the oil is subjected to. The algorithm is based on a constant that the oil is 5W20 conventional oil and the variables are the engine operation at various temps, etc as mentioned above. Using synthetic, conventional or a different weight oil will make no difference to the calculations since the math is calculated on the assumption that 5W20 is used as the only common, fixed constant factor.

I have over 70Kmi on the Spark and change the oil with Eneos 5W20 synthetic and a good quality filter. The oil and filter are changed when the 'Oil Life' indicates about 5-10% depending on the color of the oil at the time. It usually falls somewhere between 6,000 and 7,500 Mi mostly driven in warm conditions with engine up to temp. I have a similar oil monitor on a newer Range Rover and also check it in the same way with similar results. My mechanic has sent out an oil sample after 6,500 (10% left) to be analyzed and came back with good chem properties and about 1,500 mi life left. That's the math and I interpret that as the 'Oil life Monitor' working as advertised.

As far as the back pressure 'valve' in the muffler tubing..it is in fact a pressure loaded 'baffle' that moves to varying degrees to allow or slightly restrict exhaust flow to equalize back pressure at different flow speeds/pressure generated by engine RPM and operating conditions. This baffle is found only in the primary muffler....That's the math and facts...'Nuff said..

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Actually 'Big Bob" was a bit stubborn and with embedded ideas about newer tech. Very much the traditional mechanical guy he was knowledgeable on pure mechanics, had some good (and some bad) opinions and his posts about CVT's were pretty well spot on...Just thought he needed a defending since he is no longer on this site. I do, however get your "Big Bob is back ? LOL"..and yup..The thread is kinda 'LOL'. Removing a perfectly good stainless muffler with a pipe is, well..what can I say..

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All car manufactures use the same data algorithm to calculate the oil life. But you can still change your oil every 3000 miles or as much as you want.

This is not just GM. (Algorithm-based oil indicators )

"Algorithm-based oil indicators measure lots of factors and then plug the resulting numbers into a formula. Based on the answer to this complex, ongoing math problem, the indicator display will tell you whether the oil is OK, is close to requiring replacement or needs replacing immediately.

Interestingly, with these types of indicators, there are no sensors to detect the quality of the oil itself. Instead they combine data on how many miles you've driven, the temperature variations during that time and data about how much work the engine has performed. Typically, the indicator (monitoring system) will receive such data from the powertrain control module, or PCM, which is the main on-board computer. Engineers have figured out a fairly accurate and reliable way to calculate the remaining oil life this way, without having to actually sample the oil."

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Actually 'Big Bob" was a bit stubborn and with embedded ideas about newer tech. Very much the traditional mechanical guy he was knowledgeable on pure mechanics, had some good (and some bad) opinions and his posts about CVT's were pretty well spot on...Just thought he needed a defending since he is no longer on this site. I do, however get your "Big Bob is back ? LOL"..and yup..The thread is kinda 'LOL'. Removing a perfectly good stainless muffler with a pipe is, well..what can I say..

Lol.

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Retired old Gearhead that is an excellent response. Your answer is based on facts and actual experience.

You have definitely convinced me the oil life monitor does work on parameters that give it proven functionality.

Since it doesn't actually analyze the chemical properties of the oil, I will continue to err on the safe side and change the oil every 5000 miles. I drive the Spark mostly short trips with a lot of stop and go, surely falling into the severe use category. The oil life monitor always says that I am changing the oil earlier then necessary. But there is no doubt that one can hear and feel the difference fresh oil makes in an engine compared to oil that is "only" 5000 miles old.

As far as the pressure loaded baffle in the primary muffler, I never noticed any difference in performance at any speed. I got just what I was looking for, losing some dead weight and raising the exhaust volume a little bit. The exhaust was so quiet in stock form, there was a few times in traffic under light throttle where I stayed in a lower gear to until the revs where 5000+. Now there is a pleasant low level growl at higher engine speeds to give one a better feel without checking the tachometer.

With a multiple catalyst/resonator design the muffler is an overkill for the Spark's 1249cc engine. I guess it's comes down to personal preference, but the car still falls in the "quiet" category even with the muffler removed. It has a little "personality" now. There are several other modern car models that don't run a "primary" muffler in stock form.

Edited by gitsum
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Retired old Gearhead that is an excellent response. Your answer is based on facts and actual experience.

You have definitely convinced me the oil life monitor does work on parameters that give it proven functionality.

Since it doesn't actually analyze the chemical properties of the oil, I will continue to err on the safe side and change the oil every 5000 miles. I drive the Spark mostly short trips with a lot of stop and go, surely falling into the severe use category. The oil life monitor always says that I am changing the oil earlier then necessary. But there is no doubt that one can hear and feel the difference fresh oil makes in an engine compared to oil that is "only" 5000 miles old.

As far as the pressure loaded baffle in the primary muffler, I never noticed any difference in performance at any speed. I got just what I was looking for, losing some dead weight and raising the exhaust volume a little bit. The exhaust was so quiet in stock form, there was a few times in traffic under light throttle where I stayed in a lower gear to until the revs where 5000+. Now there is a pleasant low level growl at higher engine speeds to give one a better feel without checking the tachometer.

With a multiple catalyst/resonator design the muffler is an overkill for the Spark's 1249cc engine. I guess it's comes down to personal preference, but the car still falls in the "quiet" category even with the muffler removed. It has a little "personality" now. There are several other modern car models that don't run a "primary" muffler in stock form.

That's what I have said from my first post. It does not measure from the chemical properties. It's all it data collected from multiple sensors, how many miles you've driven, the temperature variations during that time and data about how much work the engine has performed. But it is not some random fancy mileage counter.

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That's what I have said from my first post. It does not measure from the chemical properties. It's all it data collected from multiple sensors, how many miles you've driven, the temperature variations during that time and data about how much work the engine has performed. But it is not some random fancy mileage counter.

Yes, you were correct. But you didn't test it yourself, you took GM's word for it.

Yes, GM's description was correct. But that doesn't mean one should take every manufacturer's claim as 100% truth.

If we could blindly believe all, the Volkswagen diesel wouldn't run dirty and Hyundai's would get better gas mileage than they claimed. Just to mention a few recent manufacturer's false claims among many...

Edited by gitsum
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Yes, you were correct. But you didn't test it yourself, you took GM's word for it.

Yes, GM's description was correct. But that doesn't mean one should take every manufacturer's claim as 100% truth.

If we could blindly believe all, the Volkswagen diesel wouldn't run dirty and Hyundai's would get better gas mileage than they claimed. Just to mention a few recent manufacturer's false claims among many...

There was no reason to test myself. I guess I took many other manufacturer's words on oil life meters without testing it over the years. The same process is in many vehicles makers. Between Chrysler, Mercedes, BMW, Honda, Ford, etc., it's proven to be pretty accurate in calculating oil life. No reason right now to reinvent the wheel.

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Opinions are great for this forum and so are questions relating to the Spark, technical or not. There are no idiots here (for now) and some have made various decisions on mods. I respect anyone doing a DIY mod..It's work that can be a valuable learning experience. Some mods work others don't..only one user did a mod the the air intake system that was zero knowledge and a backward install that caused isuues..not really bad but, well..you get my drift. I'm pretty sure, well, mostly at my age have serviced and flown everything to rotary aircraft to old piston poppers left over from WWII to finally captain a 747, C-130's and various rotary. Now retired,I know my stuff. I was very skeptical of the oil life systems in our newer car..I tested over and over..and they work to my satisfaction standard which is fairly high. Now please keep the opinions and questions going..but lets put this oil life crap to an end..it works as advertised...period.

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Let's go ahead and beat this horse some more to make sure it is dead.

The oil life algorithm in the Spark measures engine parameters to predict oil life. Is it accurate?

It appears to work good enough. But let's make sure and recognize one very important fact. The algorithm is based on a theory, not actual physical oil properties/condition. It is estimating the actual oil life based on how the said engine parameters are affecting the oil. It is not checking the actual oil properties.

For the most part this works good enough. But there are a few things that can't be factored in or accounted for by this algorithm. Driving in dusty conditions, driving in a extra humid environment, increased blow by gases in a high mileage engine. Dirt/particulates, moisture/water, and contaminating gases from combustion are three of the biggest factors in reducing the lubricating properties of oil.

I seriously doubt if sticking to the oil life meter is going to cause engine damage. But under some real life extreme conditions that a lot of cars are subjected to, changing your oil consistently before the oil life meter runs out is likely to reduce engine wear.

This is my personal opinion and you have to decide whether or not it has merit. Likely I am biased because I am a person who is a real stickler for maintenance on my cars and motorcycles. I do all my own work and it certainly doesn't hurt anything to schedule maintenance a little earlier than the manufacturer's recommendations.

Somewhere in the big scheme of things I don't think these manufacturers want your car to last forever...

Edited by gitsum
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Correct on two points. If you are changing your own oil/filter, it's more cost effective and every 5Kmi will certainly ensure your oil is always good. As I said in an earlier post the actual properties of the oil are not measured and some will have more contamination than others depending on factors like driving cold short trips (carbon), worn rings causing fuel contamination etc. Some common sense is needed when these conditions are present and maybe change the oil at 50 or 30%. One simple test is to drip a few drops of oil onto a white paper towel, let it sit for a few minutes and you will see rings of contamination such a black carbon or fuel on the outside of the ring and other colors. Basic rule of thumb is to change the oil earlier if you do alot of driving in dusty conditions, idle alot in traffic pull a trailer etc.

As mentioned before, I had the oil lab tested at about 10% and it came back good for another few thousand miles. (Synthetic). Same on the Rover. Just pull the oil stick out and make sure the oil is not all black and sooty and a strong smell of gas & when in doubt change early and use synthetic...

Oops..I think I just got sucked in to a technical 'nit pick'. Bottom line is if your car runs well and you follow the users manual..yer good to go. Look under the hood once in a while and check to make sure fluids are up to level. Keep yer tires at 40PSI..get an underbody wash (local carwash) a few times a year. and basically that's about all this car needs..if your car has a problem there are so many sensors, you will be alerted..not a high performance race car..just a low maintenence car with a good engine and good 4speed auto tranny..CVT..loads of problems that GM will fix as part of the 100K warranty rest of the motor covered for 100K or 5 yrs..soooo... Worry not and just drive the heck outta it..I do and after over 70Kmi..runs great.

Edited by Retired old Gearhead
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  • 1 year later...
On 3/10/2016 at 5:15 PM, gitsum said:

Well, just because they say it's so I'm going to be stubborn and not believe it. On my next oil change (about 2-3 months) I'll reset the oil change function. I change my oil every 5000 miles with full synthetic 5w30 SuperTech from Walmart (I don't believe the GM additive bull). I'll report back with the percentage left and then reset and go another 5000 miles with a fresh change.

I strongly suspect the second percentage is going to match the first exactly. If the parameters really include engine temp and revolutions, the percentage readings are going to have to be different.

This is going to take about 6 months, but we will have a definitive answer based on actual results, not on advertising/marketing hype.

I will look forward to reading your conclusions. 

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Slightly off-topic, but one of my in-laws trades his car for a new one every 3 years,

and never bothers doing any maintenance such as changing oil! This and other reasons why I avoid buying used cars! I have bought only new GM & Ford cars since 1964 (10 total including the 2017 Spark), and don't think have spent more than $1000 in repairs over 5+ decades. Before 1964, I was a poverty stricken college student, bought only cheap used cars, and had every problem imaginable. 

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  • 5 months later...
  • 1 month later...

OMG, you do not need a computer algorithm to know when oil needs changing.

First of all, we all have different driving habits. No computer program written by

some person out of college with a computer science degree and who is still wet behind 

the ears can encompass million different driving habits in her algorithm..

 

I use this 55+ year old method to determine if oil needs changing. Take the dipstick out,

look at the color of oil and sniff it. If it looks fairly clean (as opposed to dark & dirty) and

it does not smell burned, it is still useful oil. It will lubricate (primary purpose) and it will

carry heat out of the engine. I never had anything burned in the engine, in a couple of

million miles of driving over 55+ years. Only time I had a burned exhaust valve was when

the technician changed coolant in my 2007 Pontiac G5 and left air pockets in there which

made the engine run 10 degrees hotter than normal. It had nothing to do with oil change.

 

It is true that with fresh good quality oil the engine usually will sound like a purring cat.

However that effect disappears after a couple of hundred miles of driving. 

 

My first oil change is planned in February 2018, when the new 2017 Spark is expected

to be at about 7500 miles after 12 months of driving.  But I do keep an eye on the looks

and smell of the oil every month. Right now the oil looks in very good condition.

Edited by Bobby MSME
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Yup..Bobby correct on all counts. Both cars I do the 7,500mi or 1.5yrs with synthetic and at 7.5Kmi the oil is still fairly clear and the engines cannot be heard running from outside or inside the cars..My mechanic says I can go 2yrs without issue as long as some trips are long enough to burn off condensed water. An easy way to check for gas or water in the oil is to place a single blotter white sheet and let one drop of oil from the dipstick fall on it. Gas in the oil will form and light brown ring around the oil spot and water a outer light yellow ring. Depending on the width of the rings you can make a determination..we used this method on piston aircraft and heli's in the field along with some common sense with a visual examination..Heli's are very fussy about oil contamination while something like a DC-3 is not, but while in the humid jungle regions we had to keep an eye on the water content.

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12 hours ago, Retired old Gearhead said:

  An easy way to check for gas or water in the oil is to place a single blotter white sheet and let one drop of oil from the dipstick fall on it. Gas in the oil will form and light brown ring around the oil spot and water a outer light yellow ring. Depending on the width of the rings you can make a determination..we used this method on piston aircraft and heli's in the field along with some common sense with a visual examination..Heli's are very fussy about oil contamination while something like a DC-3 is not, but while in the humid jungle regions we had to keep an eye on the water content.

That blotter test makes lot of sense. The way I see it, 2 things in oil are bad for the engine. 1) water condensation 2) black  carbon deposits 

Water will encourage corrosion inside engine and dark looking oil can indicate overly heated oil which is never good. That is why frequent short trips are bad for the oil. We recently drove the Chevy HHR 7000 miles from Florida to Seattle to Phoenix to Florida. I had oil change done (GM's semi-synthetic) before the trip, and put on another 1500 miles since then, and the oil still looks good. It was all highway driving mostly. I ain't changing oil until it flunks my smell & visual test. May be at 10,000 miles just so there is a new oil filter installed.

 

Never let any car engine run on low oil! That is very important to prevent over-heating because low oil will not remove combustion heat as efficiently as full oil.

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