Old Euro Car Coolant Recommendations (not IAT?)

[BuckleSpring]

Hey all, looking for a “universal” coolant recommendation for my old Euro car fleet. Criteria/considerations:

• Primarily 70s-90s European cars (mostly Jaguars), virtually all with aluminum blocks and heads
• Most run silicone hoses (all the V12s) or have RTV in places (thermostat housings, water pumps, etc.)
• Want long service life/good corrosion protection- I’m lazy and don't wanna do much maintenance after an initial going-through. Old IAT is always nasty when I open a system
• I always fully flush and clean the system first (they usually need parts anyway), so no mixing with old coolant

Must be 2-EHA-free (silicone hose and RTV compatibility, and head gaskets on the V12s). Unsure how much I need to worry about silicates or the other additives I see (glycerin, nitrite, borate, amines, etc.)

In-store availability (Walmart, Advance, AutoZone, O’Reilly, NAPA, etc.) is a nice bonus but not required. Normal pricing (~$20/gal concentrate) ideally, nothing boutique like Evan's Waterless.

Current contenders:

• Peak Titanium
• Peak Final Charge Pro Series
• Zerex G-05
• Zerex Asian (any of the colors?)
• Peak Global Lifetime
• Maybe G12evo

Any other thoughts suggestions?

 

[slacktide_bitog]

Silicates are definitely not a problem in older cars because that's the only coolant that existed back then

The old green coolant was only good for 2 years, and most people never changed it that frequently, if at all, which is why they're always nasty

Zerex Original Green claims to be low silicate and good for 5 years.

Otherwise, G-05 is probably the best choice as a HOAT with silicates. Also, G05 was the first coolant not of the old green IAT type in Euro cars and has the best chance of being backwards compatible with your older cars.

Second choice would be PGL

Isn't G12 Deathcool?

 

[BuckleSpring]

Silicates are definitely not a problem in older cars because that's the only coolant that existed back then

The old green coolant was only good for 2 years, and most people never changed it that frequently, if at all, which is why they're always nasty

Zerex Original Green claims to be low silicate and good for 5 years.

Otherwise, G-05 is probably the best choice as a HOAT with silicates. Also, G05 was the first coolant not of the old green IAT type in Euro cars and has the best chance of being backwards compatible with your older cars.

Second choice would be PGL

Isn't G12 Deathcool?

I'm unfortunately aware of the old IAT lifespan, which is why I was thinking of transitioning to something newer. You don't even wanna know the corrosion hell I'm currently dealing with on the current winter project.

G12 Evo is not Deathcool AFAIK, the older G13 was(?), the newer formulation is 2-EHA free and is a P-OAT w/ Silicate.

Not sure how I completely overlooked Zerex Green, that's not a bad option. 5 years is a little on the short side, but not bad I suppose. Curious about corrosion protection compared to OAT formulations.

Why PGL over Titanium? They're both OAT, 2-EHA free, silicate/glycerin/nitrite/borate/amine free, but Titanium offers an advertised longer lifespan and improved corrosion protection (I think?)... They're also within a dollar of each other in pricing.

 

[SC Maintenance]

The problem with a list of aftermarket coolants is that in 5 years none will be available - so you will be sort of back where your starting. Of course if your starting with a HOAT it likely won't matter.

The other thing is to make sure you can get that flavor easily in concentrate if your flushing your systems. Also concentrate is easier to stock up on.

You could pull the PDS and SDS sheets and see if they tell you much or how different they are. Ignore the marketing, read the ingredients. My guess is those first 5 are not all that different from each other.

The only positive thing I could see going with G12Evo is as an OEM fluid - it should be around for a while. Is it a HOAT I assume?

 

[BuckleSpring]

The problem with a list of aftermarket coolants is that in 5 years none will be available - so you will be sort of back where your starting. Of course if your starting with a HOAT it likely won't matter.

The other thing is to make sure you can get that flavor easily in concentrate if your flushing your systems. Also concentrate is easier to stock up on.

You could pull the PDS and SDS sheets and see if they tell you much or how different they are. Ignore the marketing, read the ingredients. My guess is those first 5 are not all that different from each other.

The only positive thing I could see going with G12Evo is as an OEM fluid - it should be around for a while. Is it a HOAT I assume?

I'm not too worried about them not being available in all honesty, I can always mix whatever I get with a same-formulation of something newer... G-05 has been on sale for like 7 years at this point, and Peak Titanium used to be their 10X formulation (before they turned it into a DexClone). I can get everything I listed in concentrate form I think, as that's what I planned on doing

Of the coolants I listed in my original post:

• Peak Global Lifetime is an OAT (without 2-EHA or the other additives mentioned), Final Charge Pro is a POAT, and Titanium is an OAT w/ "proprietary cleaning agents" (which would not be unwelcome, judging by the state of some of these cooling systems)
• Zerex G-05 is an HOAT (low silicate, phosphate free, w/ nitrites)
• Zerex Asian is a POAT

I just threw the G12 Evo in there as a suggestion as I'm in the middle of a full timing belt/water pump/oil cooler/thermostat/heater core job on a CKRA Passat TDI and will most likely have a couple of gallons left over.

 

[slacktide_bitog]

I'm unfortunately aware of the old IAT lifespan, which is why I was thinking of transitioning to something newer. You don't even wanna know the corrosion hell I'm currently dealing with on the current winter project.

G12 Evo is not Deathcool AFAIK, the older G13 was(?), the newer formulation is 2-EHA free and is a P-OAT w/ Silicate.

Not sure how I completely overlooked Zerex Green, that's not a bad option. 5 years is a little on the short side, but not bad I suppose. Curious about corrosion protection compared to OAT formulations.

Why PGL over Titanium? They're both OAT, 2-EHA free, silicate/glycerin/nitrite/borate/amine free, but Titanium offers an advertised longer lifespan and improved corrosion protection (I think?)... They're also within a dollar of each other in pricing.

5 years on the short side? That's the most common OE interval in the post-IAT era

Sometimes, they also say 10 years/150k for the first coolant change, but only 5 years thereafter.

PGL has been around longer, so I think it might be better to use on older cars if you don't want to use silicate or G05. However, I don't think Titanium will be bad or anything.

 

[JHZR2]

My 30-40yo Mercedes cars get G-05 if iron block/head, and John Deere Cool Gard II if iron block/aluminum head.

 

[slacktide_bitog]

My 30-40yo Mercedes cars get G-05 if iron block/head, and John Deere Cool Gard II if iron block/aluminum head.

Why not G-05 on the aluminum heads? Wouldn't they have had G05 from the factory?

 

[2strokeNorthstar]

I ran G05 when I drove old BMWs. No more or less cooling system problems than normal. Iron block/aluminum head motors. Made it easy since I run g05 in my truck too

 

[CleanSump]

G05 in my old 92 MB was fine. Older 240D had green stuff in it so I kept changing at 5 years with green stuff.

 

[JHZR2]

Why not G-05 on the aluminum heads? Wouldn't they have had G05 from the factory?

They would have, that’s true. It would be a fine selection. Heck, even my 40YO iron block/head diesels have aluminum OE radiators, so it’s not a huge thing. But when I was dealing with HG issues on my 3.5L diesels, which are known to have HG issues due to the reduced spacing compared to the original parent design, JDCG was shown to be the best option. So as I collected more of the cars in this engine family, I just started to use the same. Then in my Cummins trucks too, which likely could use an OAT or other HD chemistry as well, but given age, etc. I figured better protection is better protection.

 

[SC Maintenance]

They would have, that’s true. It would be a fine selection. Heck, even my 40YO iron block/head diesels have aluminum OE radiators, so it’s not a huge thing. But when I was dealing with HG issues on my 3.5L diesels, which are known to have HG issues due to the reduced spacing compared to the original parent design, JDCG was shown to be the best option. So as I collected more of the cars in this engine family, I just started to use the same. Then in my Cummins trucks too, which likely could use an OAT or other HD chemistry as well, but given age, etc. I figured better protection is better protection.

I looked at the JD coolant as its been mentioned here occasionally. All they list is "proprietary". Any idea what it actually is? HOAT, OAT, etc?

 

[JHZR2]

I looked at the JD coolant as its been mentioned here occasionally. All they list is "proprietary". Any idea what it actually is? HOAT, OAT, etc?

It’s a more modern variant of G-05 as I understand it. So a HOAT with some more advanced inhibitors that perform better. The JD website used to have a lot more technical detail on the performance and testing than it does now. Maybe some is archived by the wayback machine?

 

[nthach]

G-05. ‘Nuff said, Mercedes was using it for decades until their recent switch to G-48/40.

 

[ripcord]

G-05 is readily available pretty much everywhere except Walmart. It's the easy, safe choice.

 

[BuckleSpring]

G-05 is readily available pretty much everywhere except Walmart. It's the easy, safe choice.

I ended up going with the Peak Titanium. I was going to go with G-05, but it actually turned out to be more expensive than the Peak, no matter where I looked. Kinda matters when every V12 I have takes upwards of 7-8 gallons.

 

[JimmyChainsaw]

Cars from the 70's didn't always have coolant recovery systems.In other words the coolant overflow went out to the road.You can only use the older traditional antifreeze's in those systems.The use of OAT or HOAT coolants in such a system is not recommended.

 

[BuckleSpring]

Cars from the 70's didn't always have coolant recovery systems.In other words the coolant overflow went out to the road.You can only use the older traditional antifreeze's in those systems.The use of OAT or HOAT coolants in such a system is not recommended.

All of my cars have proper overflow systems/tanks, thankfully