There is a lot of debate as to the proper coolant to use in the F136 series motors. In general, the brands/products originally recommended by the factory are no longer available (or not easily available).
In the case of the Maserati’s of this era, the generally recommended coolant choice is the Agip Eco Permanent Plus.
In the case of Ferrari (and newer Maserati’s) the recommendation has switched to Shell Glycoshell.
As far as aftermarket choices, the few that are commonly recommended are Zerex G-05, G-48, Pentofrost Nf, and the factory BMW fill.
We will go through some of the various options and what makes each of them unique.
Agip Eco Permanent Plus
This was the factory recommended fluid on Maserati in the 4200 era. Although still available (it seems to be used on certain motorcycles) it isn’t readily available. In addition to the product recommendation, the only requirement listed was CUNA 956-10.
The Agip coolant is a NAP (nitrite-amine-phosphate) free formulation and comes in the factory turquoise/blue color (not that the color really means much).
There isn’t a lot of specifications available for this coolant.
A little more information can be gained from the ingredients.
The ethanediol is the glycol itself. 2-EHA is likely used as a scale inhibitor, and finally the borates as pH buffers. However, more importantly the 2-EHA, being a carboxylic acid can serve to provide the sacrificial surface on the iron liners to prevent pitting of the liner itself.
Glycoshell was the recommendation on the F430 (and later Maserati’s as well). It too is technically still available but not easily found, especially in small quantities. Like the Agip, it too is a NAP-free formulation and maintains the same blue color.
Key portions of its chemical makeup seem to be very similar to the Agip, differing really only in a small difference in concentrations.
Based on this, it seems fairly reasonable to suspect that these two are interchangeable.
The Zerex-G48 is a regularly suggested alternative. It’s easily available, and if you like following the (inaccurate) color coding scheme of coolant, comes in the same blue.
The Zerex-G48 is said to be the same coolant sold by BMW 82141467704, which too is often recommended. It’s hard to confirm this, and likely isn’t true as their chemical formulations are infact slightly different. That said, Valvoline does recommend their G48 as a BMW compatible fill.
Like the factory fills, G48 is a NAP-free coolant. It holds many certifications for both autos and large vehicles.
It’s chemical makeup aligns closely with the factory fill.
Based on its stated properties, it seems like a very close factory-replacement match.
As this is a OEM product, very little information is available about this coolant option. Given that G05 is the recommended factory fill, it should be NAP-free as well. Likewise the formulation should be similar.
Again, the formulation looks fairly similar except for one of the inhibitors replaces the borates with sodium hydroxide.
A argument is often made against the BMW anti-freeze as these cars don’t make use of wet liners in their engine. Just because they don’t doesn’t necessarily mean to me that they aren’t suitable.
A Zerex-G05 coolant is often another recommendation on various message boards as a easier to find replacement for the factory recommended fluids.
Like the factory fills, G05 is low-silicate however it is not NAP-free (it contains nitrites). Generally meant for diesel engines, the nitrites are present to help prevent cylinder liner erosion due to cavitation of the coolant from vibration/etc.
Like a lot of diesel engines, the F136 series uses wet liners and so it is believed that the nitrites are necessary to prevent damage to the liners. There is some anecdotal evidence that this has occurred on certain occasions but it’s quite possible the liner damage was due to other reasons (e.g. neglected service intervals on the coolant causing excessive corrosion).
The G05 contains many approvals, generally from heavy machinery manufacturers/specs.
Main chemical make-up diverges slightly from the other formulations.
It’s interesting to note that it doesn’t contain 2-EHA. EHA is often blamed for damaging plastic components/seals as it’s a plasticizer, but must have been accounted for as the factory fill contains a similar amount. The removal of 2-EHA makes a reliance on the nitrite for iron pitting protection.
I will say that the addition of nitrites, although reduce liner erosion are known to cause other issues. Notably attacking the flux used to braze aluminum parts together. Notably the oil/water heat exchanger.
So, which is the right choice?
Sticking with the factory recommendation is the definitely the easiest and best choice. Outside that, finding something that most closely matches the properties of that factory fill seems to be the next best choice. Zerex G-48 seems like a closer match.
The argument against it again is the fear of liner erosion. Although I can’t find any specific studies with regards to this on Ferrari engines, looking again at the specs of the two coolants something interesting emerges.
First is a comparison of aluminum pump corrosion due to cavitation. Per Valvoline’s own test, the G-48 outperforms here.
Both coolants meet one-another in their cavitation erosion ratings.
The G-05 performs a bit better in resisting foaming. Unfortunelty I was unable to find any similar specs for Glycoshell or the Agip.
To me, the claims that G-48 will quickly bore a hole into the side of my cylinder liners don’t seem to be founded on any facts. The carboxylic acid’s (e.g. 2-EHA) take the place of the nitrite for this role. The one fact that bothers me most about the recommendation of G-05 is the addition of the nitrites which have been shown to cause damage in aluminum coolant system components. Of particular concern are the oil/water heat exchangers.
Although the user manuals are not pretty out of date, the latest data from Ferrari themselves seem to show that G48 is a suitable replacement for the originally spec’d Glycoshell.
The CARIX Premium G48 concentrate doesn’t seem to be readily available here, but looking again its a NAP-free HOAT just like Glycoshell. It’s makeup seems similar yet again to Agip Eco Permanent (sorry the below isn’t English but you can compare the CAS numbers).
Additionally, another option, the BASF Glysantin G48 is listed as “Ferrari approved” on their literature. Its composition matches very close to the Zerex G48 and originally recommend Glycoshell.
So at the end of the day, the choice is up to you. Its only recommend you stick with the factory recommended fluid brand and type. If you are unsure consult with your mechanic.