Andrew12

Researched this for about an hour plus. Thought it best just to ask. Found a lot of posts, but most were 10 years plus in age.
The car is a 2012 A8L W12.
Looks like G12++ is preferred?
G12 and G13 will work, but if car has G13, don't add G12.
Avoid G12+ due to silicates.

The coolant reservoir says G12. Assume it still has the original factory fill?

Striker2237

Just use pentosin G13 and fully remove all the old coolant when you change

MP4.2+6.0

G12++ gone from market. G13 is successor, which is basically G12++ cut with glycerin to help Audi meet its green goals. Nevermind the functionality. In Pentosin, it's Pentofrost E.

You want silicates, and specifically in a W12. Known failure point of W design motors is erosion of cooling passages due to lack of silicates. Old fears of silicate dropping out are 20 years out of date.

Audi coolant reservoirs are often mismarked on this too--they never marked the "+"/ "++" spec revisions. Need to use fluid spec schedules to see what Audi actually specs for a given model + motor. Simplified, it is basically all G13 these days, and the non-silicate flavors were ultimately found wanting and superseded.

A8L_New_England

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Welcome back!
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MP4.2+6.0

Still own and enjoy it at 55K, and currently helping brother in law get my prior 2006 W12 refurbed some at now 175K miles.

Have gotten out of habit of checking in here w/ other diversions.

A8L_New_England

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Good for you. I've laid back a little lately, also.
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Andrew12

Decided to pick up a liter of G13. The low coolant warning was coming on due to a low coolant level. I believe this was due to the weather turning colder. Light would go off after a minute or so. Took about a half liter to get the reservoir to the max level at 70 degrees. I crawled all over looking for any signs of a leak. First time I have ever added. I will monitor levels. Is it normal to have to add a touch of coolant every few years or so? Thinking probably not being a closed system.

2turbos4rings

Anecdotal experience here but basically every VAG product after about 2010-ish uses a bit of coolant. Anything that came into the garage from Porsche/Audi/VW I needed to top up. If the level doesn’t change over the next couple months I’d chalk it up to normal

Striker2237

Not sure, my W12 has never had the coolant changed based on history and tester and it's literally perfect level. Haven't seen it move even a millimeter in the year+ I've owned it despite my worrying about a leak.

My 4.0 ate a liter randomly, I have no idea where it went. Haven't had an issue since though, my Lexus cars also had some minor random consumption over the time I had them.

A8L_New_England

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I can usually tell if a car has even the smallest leak by smell. I can smell it, even if I can't find it. I attribute it to the use of plastics in fittings and radiator, etc., that seep tiny amounts. This is where I suggest a sealer of some sort, and everyone's head explodes.
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