MatthewLTL,
Ok, I just spent probably an hour typing a response to this. I apologize for any mistakes, I don't really have the time to proof read it at the moment. I am not doing this to argue with you, rather honestly inform you primarily of what I perceive as terrible decisions on your part regarding your car. I also address some misconceptions you have. This is in the interest of you, your car, your bank account, and everything you rely on your car for.
I will say quickly, Daewoos are not indestructible and that no vehicle on earth is. They are all susceptible to problems if mistreated, and problems if maintained, but probably less and with less severity. Millions of cars have come before yours and mine to create recommendations on how to maintain you car. You seem to be blatantly ignoring them and then stating that your single experiences opposing the common recommendations proves universal truth in your findings.
It has become apparent in the PPC thread people specifically tell you not to do certain things, then you do, and then you have more issues. Or people tell you do something expecting a negative consequence otherwise, you ignore it, and then the expected occurs. This is just seems like another example of that.
If anyone notices anything wrong with anything I say I encourage them to correct me or add on. I have been educated and work in the pharmaceutical field which involves some chemistry. One my favorite professors and long term academic mentors was a chemist and an automotive enthusiast. I've learned a good deal about fundamental principals of cars design, operation, maintenance, and of course chemistry in this interesting manner. I have a passion for cars, understanding them, and doing as much work on my car as possible. (Unfortunately it's a BMW so there are a bunch of things that make it tough for someone without a fancy computer system to fix all the way).
No matter your specific preferences with maintenance items, ultimately I think we can all agree (except perhaps MatthewLTL 
) that maintenance is better than no maintenance.
Additionally, none of the possible poor outcome scenarios listed below are an extreme stretch of the imagination. These are all problems that do occur in cars, even with proper maintenance. You seem like a handy person who would have no problem doing most any of this maintence.
So here we go...
1. Ethanol History:
Ethanol (EtOH) was added due to environmental legislation, not freezing issues. The idea was it replace "MTBE" (an additive to increase octane ratings) which was contaminating drinking water. EtOH also burns cleaner so and is technically better for the environment.
It however does not create as much energy so you have to burn more of it, therefore inefficient, therefore controversial (EtOH is less efficient + more expensive to buy). If you're into conspiracies, which I bet you are, some say it was the governments way to artificially increase activity in the corn market and related industries. How it effects local and market economies is another story.
2. The Law:
The law is actually a
MAXIMUM of 10% EtOH in gasoline*. The
limitation is because of it's varying compatibility with the majority of existing engines.
There is no federal mandate on minimum ethanol blends.You can still buy gas without Ethanol. It is called E0 or ethanol-free gas.
Presently there are only a handful states with active mandates (~6), and a couple of those only mandate 2% EtOH. I just checked for you
MatthewLTL,
Minnesota is one of these states with the mandate. This is probably why you think there is a minimum everywhere. But even these states have legal exceptions. For example in Minnesota:
So really, if you wanted to fill your car with it, there are ways around it, but unless you're racing I don't think anyone would take the effort because most people don't care. Depending on where you live there are more or less places to buy E0- (though rare) even in liberal places like CT, MA, and CA, it's available, often marketed as racing fuel. Less EtOH = more combustion energy = more power = better performance. As I understand, E0 may be more common in areas with lots of farming because a lot of farm equipment use carburetors and are not necessarily ethanol friendly.
3. Ethanol Properties:
Ethanol actually does freeze, but to fair at ridiculously low temperatures (alcohol off the top of my head is somewhere around -170). But just because it has a lower freezing point than pure gasoline does not mean it will drop the gas freezing point to the ethanol freezing point. Also consider that gasoline is not pure and contains impurities that can affect the freezing point (in either direction). In what we're talking about, water is usually the main impurity concerned because it separates from the gasoline and can freeze.
This is why gas line antifreeze, often anhydrous methanol + maybe another water absorbing agent, is still used in parts of America with frigid climates... even in gas with 10% ethanol.
Ethanol is
limited to 10% because it can be damaging to rubber products. More importantly it is corrosive to metals such as zinc, aluminum, and magnesium. Carburetors often contain these metals and are consequently damaged by EtOh, especially in higher concentrations. *E15 (15% Ethanol) has been approved for use in cars made after 2001, as vehicles manufactured prior have been proven to show premature damage in studies. E85 vehicles, those capable of running 85% EtOH, limit ethanol contact with zinc, aluminum, magnesium, or rubber to prevent damage from the high concentrations. I believe they also may have different fuel pump setups due to how EtOH conducts electricity vs gasoline. E15 under federal law can be sold to cars newer than 2001. Older vehicles than that have been shown to experience premature damage in studies.
I've heard 20% ethanol is supposedly going to be available, perhaps mandated in places, but there is news about some legislatures wanting to decrease the amount of ethanol in gas as it is (politics, religion, social issue discussion anyone?)
4. An Alaskan Anecdote Involing The Hygroscopicity of Ethanol:
When I was in Alaska in 2012 I learned most their gas has no has EtOH. It could be because Alaska has few (if any?) corn crops, but it was explained to me that it is because ethanol is hygroscopic, meaning it absorbs water. If too much water is absorbed a water-ethanol solution will separate from the gasoline and cause ignition issues, as water+ethanol does not explode. The ethanol, again, will promote corrosion. In cold climates (Alaska) the water will freeze and block fuel lines. Environmental/atmospheric water can be absorbed sitting in a tank underground at a station or in a storage facility. Note: after the phase separation, the water-ethanol solution will sink/the gasoline will rise to the top. If your getting old gas that has been sitting at bottom of the gas station's tank or you have been storing gas, it's possible to get some water got in there.
Ethanol's hygroscopic properties are also why marine applications may prefer E0 given that a boat is surrounded by water and extremely damp air. Though some boats have fuel-water separators which H imagine would help with this). I'm not well versed in aviation but I vaguely know that pilots do have concerns w/EtOH, probably in regards to many of the same issues already discussed and something to do with the vapor pressure of ethanol also fluctuating with altitude changes potentially causing air bubbles and engine fuel starvation.
***The main point here is that not everywhere has ethanol in their fuel. Therefore, its freezing point is a higher temperature. So the irony is, having ethanol in fuel may prevent it from freezing if there is no water contamination. That said, if water is present in the correct amount, then the ethanol will cause phase separation and increase the likelihood of problems. Without ethanol, the freezing point of the gas is higher, therefore more likely to freeze and cause problems. In reality, most people in the US don't live in a climates with common or routine temperatures below 0.***
------------------
Volume II. Now to
MatthewLTL's car more specifically (1998? Daewoo Lanos)... If you read anything, it should be this section.
5.
Freezing Gas Tanks:
I think you mean "more full" rather than "fuller". The tank capacity has nothing to do with the freezing issue. Your gas lines will freeze far before the tank does. It's all about the surface area to volume ratio. In the case of a fuel line or pump, you have high surface area to low volume. More surface area = more contact with the cold exterior. A gas tank (assuming it's not super thin and flat, instead a boxier rectangular prism), would have low surface area to high volume... less surface area, less contact with the cold exterior. Catch my drift? Refer to the gas freezing scenarios above.
6.
Engine Coolant Changes
If your Daewoo uses DexCool coolant like most GM vehicles, there are two types. I would guess you have the orange that recommends a change ever 150,000 miles (or every 5 years)... I think they mostly used this in the 90's but I don't know. I remember there is a lot of controversy with it recently because it becomes acidic well before the suggested change interval. I believe there was even a class action lawsuit. The other option you have is Green DexCool which is rated 2 years/30,000 miles. Or you may have another coolant, you can check it out.
In that your car is pretty old, you should change it considering that any past life antifreeze will become acidic and degrade rubber/plastic parts over time. With time, coolant's specific heat can also change (meaning it cannot effectively carry as much heat away from the engine- 1 aspect of this discussed in two paragraphs). Environmental contamination can also cause the coolant to become electrolytic and can/will also corrode all the copper and brass in the cooling system -water pump, heater core, radiator, and a maybe some fittings along the way. Corrosion leads to leaks, leaks leads to loss of fluid, loss of fluid leads to overheating, overheating can lead to severe engine damage. If you have an aluminum engine, overheating can often be catastrophic. In some cases, just one quick overheat can warp the metal and ruin the motor beyond practical repair.
I would again suggest replacing the coolant it at this point. It doesn't necessarily matter how miles you have, the aging process still occurs. If you
really need to
prove yourself to spend the $25 on premixed coolant test the pH of the existing coolant. Coolant is alkaline (basic). If I remember correctly usually the ideal pH is 9.5-10.5 and should replaced definitely be replaced if the pH goes below
8.3... but you should probably double check those figures.
7. Coolant to Water Ratio & Colligative Properties:
You should also consider engine coolant freezes around -40F WITH a 50/50 antifreeze/distilled water ratio (potentially lower, depending on what the antifreeze is composed of). Consider the fact that you
haven't exactly maintained your cooling system and that you don't know what the true ratio is. It is expected some coolant would slowly be lost naturally through evaporation over the years and you, being super repsonsible checking your fluids regularly, topped it off with 50/50 coolant like the average savvy person. Let's assume the car came with a 50/50 mix, in evaporation you only will lose water, not the ethylene/polyethylene glycol ]. So that would mean as water is lost, the antifreeze concentration becomes higher than 50% (say 52/48). Then you add more 50/50 to top it off because of more evaporation. Then your concentration of antifreeze is even higher than 50% (say (54/46). Repeat this for the X-many years since your car was built and the fluid never changed, and the ratio becomes way out of proportion. While I imagine with normal loss through evaporation would be a negligible issue, over 17 years this might become a factor. Luckily coolant lost through the exhaust would however be lost at a proportional late. If not topping off with 50/50 coolant, just throwing in coolant guessing the amount or not mixing with water will throw of the balance.
The ultimate point I'm getting at is the the possibility of higher antifreeze concentration, the
higher the freezing point. By comparison a 25/75 mixture will freeze at 10F, or a 32.5/67.5 at 0F (versus the -40 with 50/50)- that's pretty extreme! As you also might logically deduce, conversely, this would mean you have a higher coolant boiling point because of the higher proportion of coolant to water. Now you might understand your engine would be at greater risk of overheating or running an a non-optimal temperature (as boiling coolant is not effective at cooling the engine). I'm not saying has occurred to a catostrophic level (YET!) for sure but is just a future possibility to be aware of in that you live in a cold climate. Since you have never flushed the coolant, you have never reset the coolant/water ratio.
8. Oil Changes:
You should REALLY consider changing your oil more than every 4 years. Even if you drive a short distance, environmental exposure will decrease the viscosity, efficacy, pH of of the oil. Motor oil sitting in massive temperature fluctuations can change its viscosity over time (i.e. ~200F to -60F is pretty big). Oil also can become oxidized decreasing its efficacy. Extreme cold causes oil to permanently congeal and not flow as well throughout the engine. Motor oil + H20 creates acid that's not good for your engine. The last 3-4 points are especially true with non synthetic oil.
I know you say you don't drive on the highway or far away so I'm guessing you take a lot of short trips. One of the biggest problems of short trips is they
do not allow for oil contaminants to burn off. This is just asking for
oil sludge issues. Additionally, if your oil never heats up all the way for long enough, it may rarely flow well through the engine, thus neglecting to properly lubricate all parts of the engine.
Oil is cheap, especially if you just buy regular oil. An replacement engine is not. You might as well play it safe rather than potentially causing a catastrophic issue.
Both the Coolant and Oil changes are two things professional mechanics always comment on regarding "grandma cars"- old cars with low milage that may the maintenance they require based on miles driven, but
time and
aging of consumables is not taken into consideration.
9. Engine Block Heater:
I can easily agree modern cars are easier to start in the cold due to multiple factors. I can generalize here in New England engine block heaters (+fuel heaters) are primarily used on diesel engines due the nature of diesel in the cold. I've never heard anything about Ford specifically but this sounds like it could be one of your vast generalizations. What characteristic of Ford engines makes this the case?
If you live in a climate that gets to -60 then you definitely would have an engine block heater. (You on the other hand are living in a place that has no record of ever reaching -60F, let alone below -40F... or even -30F- and that was in the 70's.) I was told in Alaska to use an engine block heater if temps were around -20F or lower with gasoline. It could be higher or lower, I don't have much experience with regular use of them. The purpose of them is to heat the oil which becomes too vicious in cold weather. I looked at a residency program in Alaska (yes, that same 2012 trip) and everybody had them up there. Many people also had them when I visited Sweden as well. They are still an option on most cars as far as I can see. They are also available aftermarket. If you're living in a climate that doesn't get cold enough, you won't obviously won't see them because they're not necessary. In my entire life living winters between Mass, NY, and Conn I've only seen a few regular, gasoline cars with them (usually used cars or people who had moved)
10: Summary:
The reason you change fluids is because of a concept called "preventative maintenance". That logic is if you spend a little money here and there, you will have fewer catastrophic issues in the future. Again, none of these scenarios are particularly rare or out of the realm of possibility. Remember that the health of coolant can not really be determined visually. You can tell if oil is dirty or has coolant in it easily, but you can't reasonably measure it's viscosity or life.
BMW says I should get an oil change every 12 or 15k miles. But like I said, oil relatively cheap yet vital to the car. Spending a little extra money by changing the oil every 5,000 with full synthetic gives me better piece of mind. In the first 50,000 miles under warranty I'm sure the car does will survive with 15k mile intervals, but who knows long run. Funny story- I know a woman that divorced her husband and didn't change the oil in herbrand new (at the time) Volvo for almost 45,000 miles!!! The engine apparently had no real issues but did get a thorough sludge cleaning. She sold the car shortly after that after advisement from the mechanic (buyer beware!).
