Righto ... lets see if a little info really is a dangerous thing ...
...
Rodge & I both share the view that sometimes too much,
is .... but his opinion was that it should be available to be read ....
Soooo ......
At the bottom of this post is a link tooo
oooo .......
DONT LOOK AT THE BLOODY THING YET ......
At the bottom of this post is a link to one of the more easy to follow graph setups on Eth-Gly/Water properties.
Not
all of it, makes a lot of sense to me but the numbers and details match other sites/publications Ive compared it against ... and I would be particularly interested in finding out whether the viscosity of 50/50 ... in any way makes up for its other deficiencies as a hot climate "
coolant" in an inefficient cooling system.
Caution needs to be exercised when looking at the info ..... the same caution that should be applied when reading our opinions on forums and other websites.
Why ???? ... heres an example.
Theres a table in the link, displaying the boiling points of different percentage mixes ..... and
when you look at the 100/0 eth-gly/water - boiling point .... its about 200*c
YAHOO ... My XJ will never boil over again
But when you look at the XJ FSM ... my think points in the lighter colour ...
and cross reference the other tables of characteristics ......
ETHYLENE-GLYCOL MIXTURES
The required ethylene-glycol (antifreeze) and water mixture depends upon the climate and vehicle operating conditions. The recommended mixture of 50/50 ethylene-glycol and water will provide protection against freezing to -37 deg. C (-35 deg. F) ... depends on the climate huh ... and nothing about high temp protection ????
The antifreeze concentration must always be a minimum of 44 percent, year-round in all climates. If percentage is lower than 44 percent, engine parts may be eroded by cavitation, and cooling system components may be severely damaged by corrosion ... so some consideration MAY be nescessary regarding the 0.2 viscosity difference shown in the link ... or is it because chrysler arent differentiating between the eth-gly AND the added anti-corrosive products ???
Maximum protection against freezing is provided with a 68 percent antifreeze concentration, which prevents freezing down to -67.7 deg. C (-90 deg. F). A higher percentage will freeze at a warmer temperature.
Also, a higher percentage of antifreeze can cause the engine to overheat because the specific heat of antifreeze is lower than that of water... so more is not better.
COOLANT SELECTION-ADDITIVES
Coolant should be maintained at the specified level with a mixture of ethylene glycol-based antifreeze and low mineral content water. Only use an antifreeze containing ALUGARD 340-2 y. coz eth-gly isnt an inhibitor as such, and needs the additives, all the chemists test for as per the samples of materials provided by the carmakers over the years.
100 Percent Ethylene-Glycol—Should Not Be Used in Chrysler Vehicles
Use of 100 percent ethylene-glycol will cause formation of additive deposits in the system, as the corrosion inhibitive additives in ethylene-glycol require the presence of water to dissolve ... and its not the corrosion inhibitive additives in eth-gly ... but the corrosion inhibitive additives ADDED TO eth-gly.
Additionally .... when the "specific heat capacity" is examined using a table in the link ...
100% eth-gly only needs a heat amount change/influence of .66 at the XJs "normal" 93*c/200*f running temp to cause a 1* fluid temp rise .... whereas 50/50 needs .865 ... and 30/70 needs .936
So what looks good initially ...pans out to be the wrong stuff to use ... Still ... that 200*c 100/0 boiling temp might justify the "anti-boil" advertising on the bottle
Another point made in the link is the increasing of flow rates to make up for the deficiencies in eth-gly mixes.
Noooo .... bling bunnies
... this doesnt mean race out and buy some higher flow waterpump ... coz theres not a lot of point speeding up the flow into a heat exchanger (radiator) that wasn't efficient enough .... at the slower flow speeds ... Besides - the yanks have been using eth-gly for so long the factory waterpump should be right
...... and then theres cavitation issues, hot spots in the galleries ( the thing
murray referred to earlier ) and no doubt a lot more. If you want to use such a device ... go for it - its
your vehicle ... but at least know what it will or wont do for you ..... same as all the other wonder cures out there ....
Something that is missing in the link was the lower heat shedding ability of eth-gly .... but the FSM states thats a fact ... so lets give chrysler the benefit of the doubt ...
Lots of the sort of info in the link .... and even some of the FSM info is also really only pertinent to a vehicle sitting on a dyno machine/controlled environment ... or coldroom chillers .... as the constant variation in driving conditions, engine loads, wind chill, ambient temps, reflected driving surface heat, your right foot, yada yada, make driving .... a very fluid environment ... if you'll excuse the pun.
So be careful with it ....
BTW ... This is not about 30/70 over 50/50 just coz stoopid carves said so .... its about awareness of a product .... and what YOU do with it.
Im of the
opinion that 30/70 is better and use what
I use .... but even a quick trip over to the NAXJA forum will find the cooling fellas suggesting 50/50 for winter and 30/70 for summer due to their
weather extremes.
Mix ratio choice is all YOURS ..... should you choose to weigh up the pros & cons.
phewwww .... damn post is nearly bigger than the link page ....
OK .... now yaz can clickey clickey .....
http://www.engineeringtoolbox.com/et...col-d_146.html