Coolants other than Porsche's

[Overdrive]

Has anyone used any in their cars? The question came to mind when I told my co-worker (VW guy) about how hot the Boxster tends to run despite what the gauge reads on the dash. He suggested using G12 coolant, something that modern VWs/Audis use, it seems, if I ever do a full flush of the system. I told him about how it's been pretty strongly said that only Porsche's coolant is to be used, but that got me wondering why that is?

Anyone care to provide some info? Either about using a coolant othe than Porsche's with observed benefits/issues, or providing some details about why we can't use anything else in our cars. Thanks!

[healthservices]

When was the last time you removed the bumper and cleaned out the radiators? I did mine last week and I don't know if it is just in my head but the temps dropped 5 degrees.

[Overdrive]

The last time would be never, but they're looking pretty clean at the moment...might be surprised when the bumper comes off, though. The car does fine when I'm in open air cruising at highway speeds...or more, lol...the needle drops to right past the 180's dash mark on the gauge. But in the city, in traffic, or behind a vehicle on the higway the radiators don't get as much of a cooling effect and the needle will creep closer to bisecting the "0" of the 180, kind of midway between the 180 mark and the next dash, which I believe is supposed to designate 215. I know our temp gauges are inaccurate, so I always assume the car's running hotter than what's shown once it's past the 180 mark, and colder than shown prior to that mark. Even though the needle isn't touching that 215 line, I assume it's running close to that temp.

My friend just really got me wondering what the reasoning is behind only using Porsche's coolant, because if I can indeed use this G12...well, why not if it works better? I just don't think I've come across anyone on here who has used a different coolant.

I do have plans, when funding makes itself available, to do several things to cool the car down, like a low-temp thermostat, 3rd radiator up front, S oil cooler, etc.

[fivepointnine]

My s hardly goes past the 180 mark no matter what, but it has a new waterpump and lower thermostat too.....not using Porsche coolant either

[Overdrive]

What coolant are you using, fivepointnine?

[fivepointnine]

Don't laugh but it has good ol' green coolant, but I do flushes pretty regularly

[JFP in PA]

In order of criticality,

1. No particular brand of coolant is going to make your car run any cooler than any other brand, period. And don’t waste your time and money on aftermarket band-aid coolant additives; all they do is make your wallet easier to sit on.

2. The “story” behind staying with the Porsche coolant stems from the fact that it is not overly compatible with some other types or brands. When it the OEM coolant is mixed with a type it does not like, gelation occurs, leading to one Hell of a mess, and a significant expense to get it cleaned out and get the car usable again.

3. If the car was drained and thoroughly flushed of the OEM coolant, just about any aftermarket coolant compatible with Porsche engine alloys will work. But the trick is that you have to start with a totally clean system to be safe.

4. Any Porsche shop worth its schnitzel knows about the incompatibility issues and will only use the OEM coolant or distilled water (for top offs) to be safe. So if you bring them a Porsche with something else in it, they won’t know that and could cause an issue while performing normal maintenance on the car.

5. The OEM stuff is actually a very good coolant; we have seen cars 6-8 years old with the factory fill that still tested well for pH, freeze point, etc. So life expectancy should not be an issue, as long as the system is clean and the coolant is mixed with distilled water (prevents contamination and degradation of the coolant additives package).

6. All M96/97 engines run way too hot to begin with. If the radiators are clear of debris, they should be fine; but one of the biggest culprits is the OEM thermostat, which forces the car to run way too hot (do a search, this issue has been covered ad nauseum). Aftermarket 160F thermostats (same temp Porsche uses in their high HP cars like the GT2, GT3 and Turbo) will lower the general operating temps for both the coolant, and more critically, the oil (often by 20-25 degrees or more).

7. Another issue is the OEM water pumps; over time, the impeller often wears down, reducing coolant flow. Unfortunately, no one in the after market makes a replacement that is worth a damn, so you are stuck with the OEM unit. Jake espouses changing the pump at least every third year; and while that may be somewhat extreme, he has a point: They do not last forever.

[tonycarreon]

Originally Posted by JFP in PA

The OEM stuff is actually a very good coolant; we have seen cars 6-8 years old with the factory fill that still tested well for pH, freeze point, etc. So life expectancy should not be an issue, as long as the system is clean and the coolant is mixed with distilled water (prevents contamination and degradation of the coolant additives package).

took 10 years before i had to flush mine and then it was because the water pump finally gave out.

[DenverSteve]

For me it comes down to ... why? It's easier, and no down side, to simply use the factory product. No compatibility issue that way.

[Overdrive]

This is exactly why I was asking the queston, so I could get some enlightenment on the matter. Certainly it's easier to keep going with the OEM coolant, I just figured it can't hurt to ask and learn something in the process whether it ends up being a good idea or not.

JFP, thanks for the in-depth explanation. Your point #6 is exactly why I was asking, in search of any and all solutions to the hot running. I've seen it all over this board and others how hot these cars run just by their nature, excluding things like blocked up radiators and bad pumps that are problems outside of normal operation. So at least I know I'm on the right track by doing things like the 3rd radiator, lo-temp thermostat, etc., to try and cool the car off.

Thanks everybody for the info.

[thstone]

As a note to #6, remember that the reason Porsche engineers chose to install a 180 deg themostat was to improve engine emissions and to extend the oil service interval.

I'm not saying that the 160 deg thermostat will cause any problems (it won't); just saying that it was a trade-off.

[JFP in PA]

Originally Posted by thstone

As a note to #6, remember that the reason Porsche engineers chose to install a 180 deg themostat was to improve engine emissions and to extend the oil service interval.

I'm not saying that the 160 deg thermostat will cause any problems (it won't); just saying that it was a trade-off.

Nonsense. The OEM stat is there only for emissions reasons, it does absolutely nothing to "extend the oil service interval"; and, in fact, many UOA's have shown that the oil stays in grade longer with the 160 F stat because the oil is simply not seeing the amount of excess heat the OEM stat exposes it to.

[Overdrive]

I figure if they're putting a 160 thermostat on higher peforming cars that are sure to have worse emissions than the little 2.5 Boxster, it can't make that much of a difference for the worse.

I'd rather the car run cooler in general because I don't always get to cruise on the highway, and I don't want it to suffer if it doesn't have to. There's already enough things I can't get to fixing/eliminating quite yet that can knock the car out of commission, this doesn't have to be one of them.

[chitowndad]

Back in the day, I had a 1987 Camaro that comes with a stock thermostat of 220 degrees F. I installed a 180 degree thermostat and within 1 year the heads were badly carboned up... My lessson learned is to stick with what the manaufacture recommends when it comes to thermostat temperatures.

Just my 2 cents which is free and worth nothing!

-Steve

[JFP in PA]

Your 87 Camaro had other problems besides the 195F thermostat (factory specs).............

[chitowndad]

Correct and thanks for the reminder it was a 195 degree thermostat... Yep those 1980's camaros were a piece of junk. Mine spent more time in the repair shop than I care to remember.

It was that Camaro that forced me to never buy another Chevy or American made car but I did try a Dodge and that was also junk. See if the manufacturers did it right, they would put the best quality in the lowest cost cars to get you to stick with them on the upgrade, instead it was the worst quality and I never went back...

[DenverSteve]

Originally Posted by chitowndad

Correct and thanks for the reminder it was a 195 degree thermostat... Yep those 1980's camaros were a piece of junk. Mine spent more time in the repair shop than I care to remember.

It was that Camaro that forced me to never buy another Chevy or American made car but I did try a Dodge and that was also junk. See if the manufacturers did it right, they would put the best quality in the lowest cost cars to get you to stick with them on the upgrade, instead it was the worst quality and I never went back...

Let's not do this. You may prefer something else, and that's fine, but there's nothing wrong with American cars. That's all I've owned for over 30 years until my Porsches and I've never had a problem, never. We can agree to stay on topic.

[MileHighBoxster]

I continue to use Porsche products for my Boxster. It may be a little more expensive, not always, but I never have to worry about what I put in last time.

[jmatta]

I re-filled my '02 S with Porsche OEM coolant when I swapped out the factory t-stat, for the LN low temp stat a couple years back. At the time, the coolant was still original and had traveled approx 15k miles. My coolant and oil temps are considerably lower, which translates to longer engine life. I change my oil once a year at approx 2500 to 3000 miles, so I don't care if I'm not completely burning off contaminants by over-cooking the engine, though I rarely drive the car on short trips and always be certain to get it up to operating temp.

Cost cutting on coolant and oil is nonsense, when you look at the big picture.

[Overdrive]

Thanks, jmatta. I'm not looking to cut costs, though. Like I said, I'm just trying to cool this car down as much as possible and was seeing if there was any benefit from other coolants. When I can stand next to my car's right side intake to keep warm on a very cool and windy fall night even a few hours after it's been sitting in a parking space, to me that's hot in a bad way, and that's with the car operating normally.