Don't get hung up on the colour - as long as you are using something sold as 'valve save fluid' for LPG, then you'll be fine. Flash Lube is a trade name used synonymously with valve saver fluid. For instance, I use JLM which is I think, a different colour than Flash Lube.
There are other brands too - which you choose is a lot down to personal choice ( as opposed to the 'my oil is better than your oil' bun fights that periodically plague this forum, along with the E5 vs E10 sh!te as well)
Caveat: I'm no expert on different valve saver fluids, so it's best that Simon (
@Lpgc) adds his views here too (and happy to be corrected, Simon
).
Thanks Alan.
I would say that fluids like JLM, ERC and Flashlube are all well respected lube fluids.
As you've implied, Flashlube is to lube fluids what Hoover is to vacuum cleaners, the name Flashlube is commonly used to refer to all lube fluids.
It is difficult to compare the properties / protection of all the different lube fluids, because nobody has run a vehicle for 100000 miles on one lube fluid and then driven another example of the exact same make / model of vehicle on a different fluid then stripped both engines down (plus another 'control test' engine that was run without any lube fluid) to compare the protection. Yet still there has come to be a situation where some fluids are respected (like those I've listed above) as doing their job description properly, whilst there might be other fluids that are as of yet considered less well proven.
Flashlube was the first on the market and no doubt just that fact alone would be enough to give it a good start on any competition if it seemed to work (which it does). If I was asked to give a one word recommendation for a lube fluid it would be 'Flashlube' but that's because it has been around longest and is known to work.. But that doesn't necessarily mean it works any better than some of the others and I wouldn't be any less confident of using JLM or ERC. I might perhaps be a bit less confident of using a fluid that's quite a bit cheaper and seems to smell different to the norm, especially if it's from a brand that's known to be a budget brand such as ESGI.
Like you, I'm not interested in the colour. Most valve fluids are yellow but I'm not sure if that implies anything. There is a blue fluid (Vlube) but the blue fluid eventually turns green then yellow if exposed for long enough to UV light! Heh there used to be a lube fluid called 'Green add'. At least the blue stuff smells like most of the respected brands. There are different smells but most of them smell a bit like paraffin to me, and indeed some of those that list the ingredients list paraffin as an ingredient. The exact formula of most lube fluids seems to be as held as close to the chest as the formula for CocaCola but I gather they all contain something like paraffin and some sort of alcohol among other things. The list of other things must be limited because it cannot contain anything that would damage cats.
I/we did once experiment... We used neat paraffin in a lube bottle on my son's old Mondeo. The Mondeo engine would soon (usually around 20000 miles) suffer VSR if it didn't have a working lube system but he did 30000 miles in it and it didn't seem to suffer any VSR with paraffin used instead of lube fluid...
I have wondered about paying a laboratory to test a well known brand of lube fluid and tell me all the ingredients! Armed with that info I could copy the formula and start producing/selling my own lube fluid, or just let my customers know the results so they could use whatever they thought a good replacement for lube fluid. But I probably wouldn't want to start selling my own version of CocaCola small scale and then not be able to buy a can of CocaCola when I'm away from home and thirsty... If I knew the ingredients in lube fluid I'd still think twice before revealing the formula to the masses (even if I gave my customers the tip).
The Elgrand VQ engines are definitely nowhere near the worst affected engines for VSR yet still I believe they will be affected by increased VSR if run on LPG long term without a lube system fitted. I know of Elgrands that have done 100000 miles on LPG without a lube system fitted and still seemed to run OK, which they wouldn't if they were among the engines worst affected. Yet still I believe that if the Elgrand engine that had done 100000 miles on LPG without a lube system fitted were stripped down and compared to an Elgrand engine that had done 100000 miles on LPG with a lube system fitted, the one without the lube fitted would show much more VSR than the one with the lube system. Severe cases of VSR eventually lead to severe problems and loss of compression but well before severe problems and loss of compression VSR will lead to lower performance. For the cost of fitting and maintaining (refilling with lube fluid) a lube system it seems to me to be a no brainer to run a lube system on an Elgrand engine... But no need to stress if lube fluid runs out for a few hundred miles. When I bought my black Elgrand it came without a battery bracket and I usually make the lube bottle bracket attach to the battery bracket. I didn't have much time when I first bought my black Elgrand so I ran it without a lube system for maybe 2000 miles and didn't worry a bit about that. But at around that 2000 mile point I did fabricate a battery bracket and did fit a lube system... and since then I've made sure it's topped up.
It is possible to set up some LPG systems to use some proportion, in some cases a varying proportion, of petrol when supposedly running on LPG. That isn't necessarily a good idea... For starters if the proportion of petrol is high enough to protect against VSR in the same way a lube fluid does, the amount of petrol used will probably cost more than lube fluid would have cost, subtracting from the benefits of running on LPG. Secondly it can cause problems with accuracy of fuelling when running on LPG... That's because if the gas injector nozzle size and working pressure are correct to allow for the full working range of fuelling (idle and over-run to flat out at 6500 rpm) then for the most types of injector they're going to be using most of the dynamic range of fuelling they can properly meter fuel over (pushing the boundary a bit for accuracy of fuelling at the low end of the scale and at the high end of the scale). If at the low end of the scale we call on the gas injectors to measure (say) 3% less fuel than they usually would, then we effectively ask for the injectors to work over a wider dynamic range and for most types of injectors (note in case including the type of injectors fitted by the LPG conversion firms that employ these methodologies) that will ultimately lead to loss in fuelling accuracy at the low end of the scale if the injectors and pressure are set up to be able to flow enough fuel to supply the engine at the high end (full engine load) end of the scale. Related reading on how constant enable of petrol addition can mess up accuracy of fuelling on LPG
https://www.lpgforum.co.uk/viewtopic.php?p=105960#p105960 . Some firms that don't fit a lube system on Elgrands that they convert to LPG do that because they don't want to have to charge for the lube system bits or the fitting of those bits so the install takes a bit less time and they can charge a bit less for the conversion, and/or they sell it to the customer as a money saving thing when really it will end up costing the customer more in fuel costs. But they don't realise the dynamic range aspect which can in some cases (and in their cases due to injectors they fit) mess up accuracy of fuelling at low loads and/or mess up ability to run on LPG at high engine loads without resorting to even more petrol addition and even higher running costs for the customer.
