Car question - Chevy Prizm

I went to a local repair shop yesteday for a cooling system flush and fill. They had a special, $49.95. But they told me my car could not use regular antifreeze, that it needed a special “extended life” antifreeze, and the cost would be $79.95.

Is it true that my Chevy Prizm needs special antifreeze? Why? And why is it so much more expensive? Or, are they trying to pull something over on me?

The owner’s manual only says to use Chevy (then a serial number) antifreeze or the equivalent.

Can anyone help me out here?

Thanks.

It’s probably a formula that’s supposedly designed for high-mileage engines, much like how there are now oils that are supposed to be better for high-mileage engines. I’m not enough of a mechanic to know if “high mileage” products are worth the money, however.

It’s a scam. Note that they told your your car “wouldn’t take” regular antifreeze, which is patently untrue. Note also that the “required upgrade” almost doubles the price of the entire package, eventhough the labor, flush solution, etc. remain the same.

The purported advantages of some premium “extended duty” antifreeze don’t keep this from being a bait and switch: they re refusing to proform the advertised service without even bothering with the “out of stock” scam. Such advantages are possibly moot: if you change the antifreeze at the recommended interval and drive an average the antifreeze won’t get a chance to perform any “extended duty”

I assume you quoted him properly when yu said “extended” duty. Of course if you call back, he may alter his wording since it didn’t work te first time

Minneapolis gets pretty cold, of course, but if you call around, I think you’ll find that most places will happily flush and fill with regular antifreeze. Most Canadians get by on it and they are north of you. The stuff has a fairly impressive temperature range. It’s not like you’re in Alaska or the far north of Canada. Antifreeze doesn’t come in contact with moving parts (except the water pump); it flows in pre-formed channels in the block and radiator – and your channels will (supposedly) have been freshly flushed clean.

Since the mid 90s GM cars and trucks have used a different antifreeze called Dex Cool. Dex Cool is not the same stuff as the Prestone you buy down the street. It is an extended life (100,000 mile / 5 year) formulation. The corrosion inhibitor package is much different than standard ethylene glycol antifreeze.
Dex Cool is and has been controversial. Here is a page that discusses some of the problems and solutions. Based on what I have read, some if not most of the problems can be laid to improper maintence, not the Dex Cool.
Anyway as far as it being bait and switch, lets see. Standard ethylene glycol recomondations are either one change per year, or change every 30,000 miles. 1 change per year for 5 years at $49.95 or 1 change every five years for $79.95. In the second example 3 changes in 100K @ 49.95 vs 1 at 79.95. You tell me which is cheaper in the long run.
This is the same as if a shop was advertising a $29.95 oil change special, and you brought in a car that requires synthetic oil. Is it bait and switch if the shop insits that you use the correct oil for the application? If the shop bows to your wishes and installs the inferior oil, if engine problems occur, whose fault is it? Is it your fault for insisting on the wrong oil, or the shops fault for doing what you instructed?
Chemicals in modern cars are not all the same, and no the same between different car makes. Many times the “standard” rules that we grew up with don’t apply.

As Ricksaid, many GM cars use Dex-Cool. Whether your Prizm uses it, I don’t know. I did look up a '99 Prizm, and my info showed it used non-Dex-Cool antifreeze and had a replacement interval of 30,000 miles.

Dex-Cool is noticeably more expensive than traditional antifreeze. In theory it’s cheaper to use because of the extended service intervals. It’s not as much more expensive as the difference between $50 and $80 suggests, but that price difference is almost certainly because the $50 is a lowball special price designed to be competitive, whereas the $80 is a “regular” price.

It has nothing to do with high mileage engines.

It’s not necessarily a scam in the way KP suggests. There are three possibilities: a) your car actually calls for Dex-Cool; b) it doesn’t but the dipwads at this shop think it does; and c) it doesn’t and they know it. C is obviously a scam, but B is a more common scenario. Unfortunately, lots of people who earn their living doing auto repair are poorly trained and not fully competent. They cost customers extra money not by nefarious design, but by exerting their ignorance with an air of authority.

The antifreeze protection (temperature range) of Dex–Cool is the same as traditional antifreeze. They’re both ethylene glycol. The difference is the additive package for corrosion resistance.

It is generally not a problem to switch from Dex-Cool to traditional or vice versa. Many GM cars have been changed from the former to the latter because of the problems Rick mentioned. GM cautions that the system needs 100% Dex-Cool in order to have the extended life claimed.

Sometimes, however, it is a problem to switch from the type of antifreeze used at the factory. It’s not common, but there have been cases of cars that develop severe corrosion problems from doing this. I’ve read about it in some industry sources and have no doubt of it, but I’m sorry I don’t have a link or know enough about it to explain it fully. It essentially has to do with the different effects of the various additives used and how the metal in the system reacts to them. The additives bond to the metal and are not removed by flushing. Getting different additives in there, often in conjunction with a new metal part (e.g. water pump) that doesn’t have the same stuff bonded to it can kick off a chemical chain reaction that starts eating pumps, heads, blocks, radiators, etc. In light of this, it’s not unreasonable for a conscientious shop to insist on using the factory-type antifreeze.

The best advice I can give is to stick with the type of antifreeze used at the factory, and flush it at least as often as recommended. In my experience, more often than not the acidity level (corrosiveness) of the coolant reaches an undesirable level by or before the maintenance interval.

Clarification: by “100% Dex-Cool,” I mean no other type of antifreeze mixed in with it. I do NOT mean use pure antifreeze with no water. For most climates, a 50/50 mix of antifreeze to water is recommended. For severe cold, up to a 70/30 mix is permissible.

No matter what color coolant you use, the antifreeze/antiboil part will last for several years. The part that wears out is the water pump lube. You can get a little can of water pump lube/ antirust stuff, and add it once a year. If your coolant still floats the right number of balls in the tester, you’re good for another year.

Color is just a matter of dye, and there’s no correlation among makers between the dye used and the additive package used. You can find antifreezes of different types with the same color, and of the same type with different color.

The antifreeze/antiboil property lasts forever.

While the additives include water pump lube, they also include corrosion inhibitors, which get consumed doing their job. Just adding water pump lube, or even corrosion inhibitors, might prolong the effective life of the antifreeze to some degree, but it’s very rare to not have some corrosion accumulating. It’s also not unusual for coolant to develop an electrolytic potential, which can foster corrosion. The only way to negate these problems is to flush the system.

Balls floating in the tester, or any other indicator of specific gravity, only measures the protection against freezing. It won’t change unless the antifreeze to water ratio has been disturbed. This test gives no indication of whether you’re good for another year or not.

The test that will tell you how much longer the coolant can be used is to measure the pH. Typically, coolant with traditional antifreeze should be changed when the pH gets down to 8-8.5, and with extended-life antifreeze when it gets down to 7-7.5.

Here’s some further reading:
http://www.cartalk.com/content/columns/Archive/2000/August/08.html
http://www.phmeters.com/New_Folder/antifreeze_application_note.htm
http://www.aftermarketnews.com/default.aspx?type=wm&module=4&id=3&state=DisplayFullText&item=5514
http://www.babcox.com/editorial/tr/tr110046.htm
http://www.aa1car.com/library/coolant.htm

As Gary T pointed out this is not always true. If the PH gets too low in the sytem, a galvanic reaction will occur. This will cause the aluminum in the cyliner head to be eaten away. if this goes on long enough, the coolant will leak. The repair at this point is a new cylinder head as there is nothing for the head gasket to seal against.
You can buy a shitpot full of antifreeze for what one cylinder head costs.