There is an additive know as TK-7 that actually works. It shouldn't, but it does. I have been using it for decades in all kinds of engines.
I don't know how many of you know who David Vizard is, but he is VERY respected as a journalist, and more improtantly as an engine builder, and is now providing services to NASCAR teams and teaches at the University of North Carolina at Charlotte in the race programs. He is even a Brit.
Here is some testing he has done on this stuff:
Motortec Magazine - www.motortecmag. com (dead link)- January, 2001
TK 7 Fuel Additive - Page 1
I should warn those of you who are into instant gratification that this is going to be one of the longest tests you will read. Indeed it rivals my 22 page article in, if my memory serves me right, the April '81 edition of Popular Hot Rodding entitled 'The Great Nitrous Oxide Shootout'. If you don't want to wade through, or cannot wait to get to the test results then go to the sidebar entitled "TK7 Test - Quick Check" at the end of this feature.
Normally product tests would be in our product test section but in this instance I felt there was so much of General Interest in the testing of the TK7 that it warranted going under that heading. I wanted to both congratulate and condemn the FTC (Federal Trades Commission) and thank a number of companies that helped out along the way. Also there are psychological aspects and associated tales worth telling as it all contributes to how many of us see additives and their role or place in the market.
Additives - General Reputation - Snake Oil !
You would think that only the youngest and most naive among us would whole heartedly believe all the claims made on additive bottles. But there is, in most of us, an element that wants to believe, if only to a minor degree, that the claims on the bottle have some foundation in truth. If you want proof of this look no further than the staggering sales of age defying creams. Maybe modern science is just now producing something that works but up to the '80's I'm sure every single bottle and jar sold was substantially misrepresented. This has been my experience with automotive oil and fuel additives - a lot of hype and not much else.
I have been dyno testing additives since about 1964 and one thing is for sure - they have, in my experience, the highest rate of any product group for failing to work. So much so that by the late '70's, after a couple of dozen additive tests, all of which failed to deliver one iota of the power increases claimed, I stopped testing. The principle reason was because the salable editorial I was getting from such tests was almost zero. I say "almost zero" with good reason because there were some incidents worth a few words. One was when I was testing a lot of performance parts for a book I was doing on the Ford 2 litre Pinto motor.
I had built a dyno mule motor, which, in base line form, would click off near identical power curves time after time from one week to the next. I had just finished a series of tests and was getting ready to pull the motor from the dyno when a young man with salesman written all over him came into the shop. Guess what - he had the latest and greatest oil additive the world had ever seen and had, as far as he was concerned, all the right pieces of paper to prove it.
After a cursory look at the printed blurb I said "we have a test motor and a dyno right here - let's test it". It was apparent that this young man had never even heard of a dyno let alone seen one. After a very brief explanation of what a dyno did he agreed to a test.
To establish a baseline five power curves were taken. These all fell well within 1.5% of each other so were used to get an average result. Next the additive was added and the motor run as per instructions for 10 or so minutes to let the additive do it's stuff. The "after" power tests were then done. Over the 2500 to 7000 rpm band tested the motor lost an average of 0.2 of a horsepower. A change that small is within experimental error but if the product had given even 1% gain tests would have almost certainly shown it. When confronted with the results this young salesman looked me right in the eye and sternly commented - "This proves to me that dyno's are a waste of time !" The need to believe in this product, regardless of strong evidence to the contrary, over ruled all.
Knowing It Doesn't Work
Of course there are those that know the product they are touting does not work - but they are going to sell it anyway. A few years ago at SEMA I approached a senior staff member of a company that was throwing huge sums of money promoting the sale of a well-known and somewhat controversial additive. I approached the person concerned and introduced myself in my capacity as a tech writer. I inquired about the possibility of performing some comprehensive testing to establish the worth of the additive for once and for all. The interesting thing is that my suggestion was very well received and it seemed like this gentleman could not do enough for me to help these tests get published. He rounded off what he thought would be the end of the conversation with comments along the lines of "we will get a motor on our dyno and call you when the tests are ready to be run". To this I replied "well no - I had in mind to use my own dyno so that the results will be completely independent (I was subtle enough not to add "and fudge free")". It was obvious this gentleman was amazed that a tech writer actually owned a dyno but more to the point his whole demeanor changed. With what appeared to be a far more reserved disposition he informed me they would organize something and let me know. I never did hear back !
From the forgoing it should be easy to see most of my reasoning behind giving up on additive tests - it's a waste of time and usually my money. But there is another. Namely that many additive manufactures (like the one just mentioned) seem to have big advertising budgets and spend large sums advertising or sponsoring events. Selling a story about a massively hyped additive that does not work to a magazine earning hundreds of thousands of dollars annually in advertising from that company is, to say the least, difficult! If the fact that up to about the mid '80's I had borne the cost of dyno testing products is taken into account it won't be difficult to see that for me, testing additives was quickly loosing any appeal whatsoever. The reality was a bit like standing in the workshop men's room and flushing hundred dollar bills down the toilet. If I sound a little pessimistic about additives excuse me, but I think I have reasonable grounds for doing so. All this led me in the mid '80's, to adopt a policy of "no free dyno testing", especially for additive manufactures.
Octane Testing - a Different Way
During the early '80's the fuels we were buying at the pumps in the US were seemingly at an all time, post '50's, low in terms of octane value. That this was so appeared pretty much common knowledge. It was also apparent that any fuel company that could advertise higher octane on the pump was going to sell more fuel. As a result there appeared to be an "octane war" brewing.
Having had some experience with fuels and ways and means of raising octane values I was aware that it is possible to formulate a fuel that showed well in a CFR octane test motor for R+M/2 figures but did not resist detonation significantly better in a road motor. Why would a fuel company do that ? At the time brewing octane into unleaded fuels was expensive but making them look better on the pump for the purposes of sales was not. What I wanted to find out was just how good (or not as the case may be) these higher-octane fuels were. A CFR test was not going to tell me anything I did not already know from reading the labels on the service station pumps.
Different Test Procedures
At this point I felt a different kind of test was needed. One that was more applicable to the motors we drove on the street. The test I conceived was to use a very high compression (14/1), short cammed, small block Chevy and test the power output of fuels rather than doing a direct test of their Octane number. The logic is simple - we don't care what the octane value is just the amount of power at the driving wheels. If you were offered 50 octane fuel that would deliver double the power would you worry about having to retard the timing 20 degrees if that's what it took? No - at least not if you are in your right mind. This was the concept of my test motor. It would test for what we might call the apparent octane value of the fuel. How resistant it was to detonation would be measured by the amount of advance that could be used before a knock sensor found detonation. How effective it was as a fuel would be measured by how much HP was developed at the test speed of 3000 rpm !
With an intake manifold coupled to the city water supply the temperature of the intake charge, a key issue when testing octane, could be varied by as much as 70 degrees F. The following chart shows the test procedural differences between Motor Octane Numbers (MON) and Research Octane Numbers (RON). The higher temperatures of the MON test typically result in numbers about 8 octane less than the RON test.
``CFR Octane Motor Test Parameters
Inlet Air Temp
300 F (149 C
125 F (52 C)
Water Jacket Temp
212 F (100 C)
212 F (100 C)