I'm just a member like you all seeking new information. I only found out about this stuff due to "Running Too Hot" having posted the link.

However, as I understand it, depending upon your Mercedes, the pressure cap should only be rated for 10-12 PSI anyway. The radiator cap maintains the pressure in the cooling system, and in most cars, that's usually about 14 to 16 pounds, which is intended to raise the boiling point of the coolant mixture. As Evans already has a higher boiling point of 370-375°F, this added pressure is totally unneccesary...

Changing the pressure cap is both a longevity and a safety issue. First, you don't need the additional pressure to reduce the boiling point further. So, having a lower pressure system will increase the longevity of the hoses, as well as prevent a high pressure coolant release that could cause injury. And, keeping the system totally closed will prevent any coolant loss, as well as the introduction of any contaminants. Also, since the coolant is hydrostatic (it absorbs water), it is best to keep the system totally closed to avoid having it do so, as water is a corrosive impurity in this system.

BTW, Evans also eliminates the need for using Redline's Water Wetter, as it already serves the function better by totally eliminating all of the problems that WW is designed to overcome.

And, when you switch over to Evans, a sticker for the engine compartment is provided to advise any service technicians that this is a closed system consisting of a non-aqueous coolant. And that under no circumstances is anyone to add water or conventional antifreeze to the cooling system.

I will call Evans again tomorrow, and see if I can get one of their reps to check my answers for accuracy, or to answer these questions for you directly.

__________________

Scott Longston
Northern California Wine Country...
"Turbos whistle, grapes wine..."

While you're at it, ask for

- an employee number
- an employee's discount
- and a commission from all the sales to mercedesshop members!

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Rainmaker
93 500E, 43k mi, Pics of upgrade parts
Evo II Wheels on Dunlop FM901 235/45x17s
94 Facelift
RennTech CF Airbox
RennTech ASR Defeat
RennTech Chip
1st Gear Start
97 Range Rover 4.6 HSE Vitesse, Yellow, "Tonka" (sold)

Golly Mr. Longston, I've been dumb! Read through all the technical stuff about NPG and saw the development statement, but didn't read NPG+ info. Thanx for your follow-up. I'm due a anti-freeze change now and will try this product. Installation date in October. Again, many thanks for your thorough notes! Roger

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Roger
1983 300CD 246k sold
1998 C230 52k
1980 450SL 75k needs AC
1999 Subaru Outback Ltd 43k

When I spoke to a tech at Evans today, I asked them to check my answers for accurancy, and got a "Thumbs-Up"!

One thing people should be aware of about this product is that the NPG starts out being a lavender, or purple color, but after being heated and cooled it will slowly turn brown and look like tea. The NPG+ will start out looking like tea, and will turn darker over time. This in no way affects the quality of the coolant, but it might appear to someone who doesn't know any better that your cooling system looks rusty, and needs to be flushed and changed.

__________________

Scott Longston
Northern California Wine Country...
"Turbos whistle, grapes wine..."

"... but it might appear to someone who doesn't know any better that your cooling system looks rusty, and needs to be flushed and changed."

Hmm... they're going to have to work on the aesthetics of NPG+. I don't think the public is ready for a product that looks like it's based on rust under normal operating conditions.

Watch out for car sellers touting NPG+ as the reason for rust colored coolant

Do any of the traditional MB part sources carry a 7 lb. cap?

Sixto
91 300SE

Funnny that you ask...
I was installing a new air filter, and happened to notice that my coolant reservoir cap was labeled "17 lbs."
Check your caps, it should say it.

__________________
2006 E350 w/ 155k miles (Daily Driver)

Previous:
1993 300E 3.2L Sedan w/ close to about 300k miles
2003 E500 Brilliant Silver (Had 217k miles when totalled!)
1989 300E with 289,000 miles (had for <1 yr while in HI)
03 CLK 500 cabrio (Mom's)
2006 C230k (Dad's)
1999 S420 (Mom's/Dad's)
2000 C230k Sport sedans
2001 CLK320 Cabrio (Mom's)
1995 C280 My First Mercedes-Benz... (155k miles. EXCEPTIONAL AUTOMOBILE. Was Very hard to let go of!)

Scott Longston,

Good job, man! Hope the stuff doesn't suck, or you're gonna get flamed by association! But in any case, I justed wanted to note that I appreciate your thorough and comprehensive explanation of a subject that you didn't even bring to the fore!!

Hope that didn't sound sarcastic...I meant my comments as a compliment

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"If God had meant for us to walk, why did he give us feet that fit car pedals?" Sir Sterling Moss

Michael
2014 E63S Estate
2006 SLK55
1995 E500
1986 Porsche 944 turbo

What ever happened??? Did anyone ever test this product?

Well, guys, I have read the thread with great interest as my cars seem to be running hotter this year and I have done the usual things like others have reported on the site. I have even flushed the cooling system with the MB citric acid solution, all to no avail.

When I read the report on this Evans product, I was hoping I would see where it reports it lowers engine coolant temperatures. I did not see it and while I understand how it prevents boil overs and all the ills associated with water based coolants, I do not believe it even makes a claim to lower engine coolant temps as none of the material's characteristics would suggest it should lower coolant temperatures.

I also did not see anything about how it fares in comparson to the water based coolants with regard to its thermal capacity and heat transfer characteristics. I did see some stuff that seemed to ignore the benefits of nucleate boiling, a very efficient and effective heat transfer mechanism of water based coolants and categorize all phase changes in the coolant as a form of cavitation, which we would all agree is not good.

Anyway, I am still looking to make my cars run at their normal operating temperatures in warm weather, especially under load or in stop and go traffic. Used to be my 240D seemed to have an invisible peg at 87 or so degrees C.

Jim

__________________
Own:
1986 Euro 190E 2.3-16 (291,000 miles),
1998 E300D TurboDiesel, 231,000 miles -purchased with 45,000,
1988 300E 5-speed 252,000 miles,
1983 240D 4-speed, purchased w/136,000, now with 222,000 miles.
2009 ML320CDI Bluetec, 89,000 miles

Owned:
1971 220D (250,000 miles plus, sold to father-in-law),
1975 240D (245,000 miles - died of body rot),
1991 350SD (176,560 miles, weakest Benz I have owned),
1999 C230 Sport (45,400 miles),
1982 240D (321,000 miles, put to sleep)

Thought I would pulse the audience - anyone give this a try yet?

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94 E500 (Silver/Black)

I've installed the NPG+ coolant in our 1999 Subaru Outback Ltd. When temps are at 25F, engine coolant temp seems to get to operating temp in 2/3 time or miles traveled. Heater comes up much quicker. Car seems quieter. At operating temp - no difference in temperature. I'll be checking gas mileage over the next few months. I am still waiting for our 100F+ summer to see about engine temp with AC at speed and at idle in trafffic. Probably will change our C230 at next service.

__________________
Roger
1983 300CD 246k sold
1998 C230 52k
1980 450SL 75k needs AC
1999 Subaru Outback Ltd 43k

Well it only took 9 months to get a response , but thanks Roger. I will need to see how it goes when it gets warm agian for your test. Living here in the SE my big concern is the heat.

Thanks and good luck - looking forward to more updates.

Steve

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94 E500 (Silver/Black)

Was reading this old thread and wondered if any users of the NPG+ coolant could report how it has performed over time and in summer time temps?

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JD

Still runs well with NPG+, I get better mpg with short stop runs ( I assume engine doesn't cool down). Overall, the engine seems to run quieter. Occasionally, the temp rises about 5* with AC on and hot weather (95* plus) - as soon as the get back to cruise at 35mph or more it drops back to 85*. I hope this helps.

__________________
Roger
1983 300CD 246k sold
1998 C230 52k
1980 450SL 75k needs AC
1999 Subaru Outback Ltd 43k