I recently got the oil changed in my 2004 Honda Civic, and was given the choice between synthetic and regular oil. I just shrugged, and said “whatever’s cheaper”. I was told that the regular is cheaper.
Is there any reason why I would want the synthetic instead? As far as cars go, I care about basically two things: good gas mileage and not having to change the oil very often. Would synthetic motor oil make a significant difference in either of those?
The viscosity of your oil can affect your gas mileage. It shouldn’t affect you to use the same viscosity synthetic vs. mineral, but all viscocities have tolerances, and I’ve heard (but not personally confirmed) that some synthetics are on the “thin side” so that they can have less viscocity and claim better MPG.
Second part: no, you won’t have to change oil as often with synthetic to get the same results as mineral oil. How often do you change your oil now, though? Maybe you can reduce the frequency of oil changes by just changing your oil less often anyway. Because you have a very well made engine, you can probably change your oil every 5 to 8 thousand miles using mineral oils without any ill effects, although to protect yourself within the warranty period make sure you follow the manufacturer’s recommendations.
The synthetic oil is recomended for high preformance cars. The owner’s manual for our Corvette has, in all caps, to use only synthetic.
Just another example of it being a hole in the road we pour money into.
Synthetic motor oil is a wonder of the technology age. Simply put, it is far superior to what is called “dino oil” in many ways. Natural motor oil loses its viscosity much more rapidly than synthetic (this is the “viscosity breakdown” you’ve probably heard of), and needs to be changed much more often - 5-7000 mile intervals is OK for normal daily driving.
Synthetic oil is a lot more expensive, but you don’t need to change it very often. 30,000 miles between changes is normal. Therefore, you pay more at first and reap the benefits later. Further, since it is a concoction of chemicals, there are a number of additives that are beneficial for long-term lubricity of the moving parts of a modern engine. Dino oil can’t compete.
While normally specified for performance cars, it is just as easy to put it into a daily driver. I put synthetic in my highly modified Mazda RX-8, but I also put it in my wife’s minivan. So, go for it.
Eh?!? :eek:
Did you mean 10,000?
If you think the synthetic oil is expensive try running an inferior oil and see what a new engine costs. 
30k is maybe a bit on the high side, but my wife’s BMW doesn’t look like it’s going to ask for its first oil change until about 17k.
seriously 17k for your first change? that strikes me as a good way to make sure your bmw dies an early death. am I nuts to think that changing the oil MORE often is the single best way to insure a long life for the engine?
http://www.canadiandriver.com/news/020312-5.htm
from that post "Change your oil and filter regularly. “If there is any one maintenance activity that will extend the life of your car’s engine, this is it. Considering the relatively low cost of oil and filters, this is the cheapest insurance policy your car will ever have.”
the only thing he puts higher than oil changes is getting a car you truly like as you will be spending a crap load of time in it while attempting to drive 2million + miles.
everyone with a ton of miles on a car also takes very good care of the car and regular oil changes are always a part of that care. and its not like its all that expensive for an oil change.
Anne,
With an '04 Civic, your two choices are synthetic blend or synthetic.
Your car specs a 5W20 oil meeting Honda’s standards for 5W20.
All oils that meet your spec have formulations that are properly considered synthetic blend. All of these oils are very nice oils.
This is assuming, of course, that you didn’t go to a sleazy quick-change place that puts bulk off-brand conventional 10W30 (just about the cheapest real oil you can get) in the car of anyone who doesn’t ask for synthetic. Those places still exist.
I have devoted a ludicrous amount of time (think Asperger’s obession) to studying motor oil, and I have reached the following conclusion:
“. . . the only quantifiable advantage to running synthetics is having to change the oil less often if you use Amsoil or Mobil1 Extended Performance, and then only on CONVENIENCE grounds. You’ll never save enough on the labor from oil changes to make any noteworthy cost savings. Regular oils are $1-2 per quart, good synthetics are $4-7 per quart.”
Twenty-weight motor oils like 5W20 all tend to be very close to the same viscosity, so you won’t find fuel economy advantages there. All blenders avoid the slippery end of the twenty-weight viscosity like the plage, because wear levels there go up exponentially versus at the top end of the grade.
Synthetics won’t let people who do a LOT of short trips or city driving in heavy traffic run long intervals.
If you drive in the kind of traffic that I expect your location tag implies (super-heavy) then change your oil at Honda’s severe service guidelines and use any name-brand 5W20 motor oil out there. Your Civic’s engine will likely outlast the rest of the car or your interest in driving the same car for years.
Let me know if you have a standard suburban drive on non-jammed highways, and I’ll reconsider my suggestion.
Previous oil threads:
Synthetic vs. mineral oil for cars: http://boards.straightdope.com/sdmb/showthread.php?t=358622&highlight=synthetic+motor
Oil Change Intervals: http://boards.straightdope.com/sdmb/showthread.php?t=352827&highlight=synthetic+motor
Oil changes every 10K miles - really?: http://boards.straightdope.com/sdmb/showthread.php?t=335176&highlight=synthetic+motor
The BMW is basing its decision to ask for an oil change on a fairly sophisticated algorithm that includes paying a lot of attention to facts like hours of operation, throttle settings, operating temperatures and gobs of other factors the car’s computer has access to. It’s not rolling a pair of twenty-sided dice under the hood and then consulting a chart.
The algorithm also assumes you’re running a certain kind of synthetic. Consult owner’s manual for specifics, but I’m thinking ACEA A3 or ACEA A5. Make SURE you don’t deviate from that specification when you change the oil, or you’ll turn that BMW into a $30K motor oil failure research lab.
GM has a similar system on most of its cars and some of its trucks.
DaimlerChrysler uses a system (mostly on Mercedes models, IIRC) that relies on an algorithm and a primitive built-in oil tester. I think the oil tester basically measures the oil’s electrical conductivity.
My Honda Civic has a “Maintenance Required” light that flashes when I’m supposed to get the oil changed. Does anybody know how that works? I had to rely on that this past time I had the oil changed- the place I go to uses a Colorforms-style plastic thing instead of a sticker on the windshield, and it had fallen off. The new one’s been there less than a week, and is already starting to fall off.
Unfortunately, I do 
The car is used mostly for commuting and the occasional weekend trip. When I get home, I’ve usually been in traffic for 30-45 minutes- the last thing I want to do is drive any more. Fortunately, I live within walking distance of 4 supermarkets and a whole bunch of restaurants and shops.
Typically it is a counter that counts miles since the last time it was reset. At the preset mileage the maintenance required light is lit.
BMW, MBZ, and some GM late model cars excepted.
Really folks, 30K between changes is normal for me with a product like Mobil 1. My Mazda is new, but the minivan I referred to has had two oil changes, and it just turned 60,000 miles. I also own a daily driver Dodge Neon with 183,000 (no, not a typo) miles on it. If any car needs help living a long life, it’s a Neon. Still, 30K between changes for the past 8 years.
I actually work at a company that makes the additives that go into motor oils (detergents, dispersants, antioxidants, etc.). I always use synthetic oil.
Synthetic oils not only experience slower viscosity breakdown (so they retain the lubricity characteristics your engine needs, longer), but their slower breakdown means that the other oil additives remain active longer – in particular, the detergent bases don’t get neutralized as quickly by the acids generated by oil breakdown.
At work we’re required to run a lot of engine tests for the motor oil companies that we sell additives to – tests to qualify the additive package and motor oil for ILSAC or other certifications (look on your quart of motor oil for the little starburst-like seal). Synthetic oils leave the engines markedly cleaner than the equivalent natural oil (in terms of deposits, laquering, corrosion, etc.).
Now, whether or not it’s cost effective to purchase the more expensive synthetic for the engine cleanliness you get, I can’t help you with. From my point of view, you’re all already getting a great bargain on motor oil (compare the price of a quart of oil to the price of bottled water some time). 
Assuming that any engine uses some oil--------even the minimum.------
--------Changing your synthetic oil at 30,000 miles means that you have already changed it through natural loss at least 3 times, maybe more.
You just don’t realize you have already changed your oil at least a couple of times before you really physically did change it.
Synthetic is overated.
Sorry but your math does not hold up. My engine holds about 7 quarts. It uses about 1 quart of oil every 8,000 miles or so. In 30,000 miles, I will have had to add about 3 quarts, less than 1/2 of an oil change.
Plus adding oil does not do anything for the gunk still in the crankcase.
This makes absolutely no sense.
Re: extended motor oil change intervals> NYC cabs were tested by CONSUMER REPORTS-they found that change intervals of up to 8000 miles were fine. and: the paradox about oil filters; a new filter will pass more particles than one with 3000 miles on it. As for synthetic oils; the only benefit is seen on vehicles tha run under severe conditions 9extremes of heat and cold, short trips, dusty conditions, etc.). It does seem that a 3000 mile interval is too short-it results in big profits for Jiffyl;ube, though.
I spent some time researching how Honda does this.
No one seemed to have an answer for the Civic, although I’m sure if I were to go to a Civic hobbyist board and ask I’d get a competent answer.
I do know that the Honda Insight has a mileage counter as you described.
The Honda Oddyssey minivan has a GM/BMW-style algorithm in place, at least in certain model years.
Wow, that’s a lot! Most of the cars I’ve had take about four. Is it an air-cooled Porsche?