My fatherwas an engineer. Nothing special he was a Civil Engineer but one of the younger brothers became a Chemical Engineer and was working for Morton Thoakol when the rocket fuel plant in Henderson, NV blew up.
His take: The addative industry is based on the notion that there are products out there that the auto makers and the oil companies KNOW are a panacea and would work wonders on your vehicle, except they are in a comsperecy and are withholding those miraacle products from you
in order that you burn more fuel, in the case of the oil companies or that your engine wears out faster, in the case of the auto industry.
Now that I'm getting old, coming up on 60 real fast all I can say is I remember well when a family car or truck back in the 50s or 60s that ran well and routinely right up to 200,000 miles was as rare as hens teeth.
The the developement of fuel injection, computers, air/fuel metering etc the modern car is much more reliable and trouble free than cars were in the past and they already get significant better fuel econemy than even my moms 1968 Dart did with the 225 slant six.
There is no cadnium ring to put around your air filter that excites the ions and increases you fuel economy to 100 mpg. There is no miracle addative to instantly adds 40 mpg.
I had a buddy many years ago that knew little to nothing about cars and engines in particular. He owned a series of 3/4 and 1 ton Dodges to pull this huge boat he had. Problem was he's on;y buy it with a 318 in it every time and everytime he'd try and to more work and get better fuel econemy than was possible.
My favorite was the gallon milk jug full of distilled water that was hooked to the port in the carb that drew water vapor into the air/fuel mixture ,thus making it burn at a lower temperature anf thus causing less wear and tear on the motor.!?!?
I akked just how that was possable and didn't it serve to reduce to energy available in the fuel thus decreasing power rather than the inverse? Nope, guy at work told him about it and he had a zillion miles on his Dodge and got 80 mpg.
Then one night the tow truck showed up at the house with his truck. Dead, dead, dead. If you try and pull the old Horshoe Bend Hill pulling a huge boat with a 318 at 175 HP BEFORE you water the fuel it sort of implodes.
I pulled it apart, showed him the bent valves, and the bent rods and the holed pistons and.....
He assured me it couldn't have been the Wonder H2O system. Then he balked at putting a 360 with a 4 barrel back in the truck with a cam to actually produce horses where he needed them in the rpm range. It was too exspensive. This from the guy that was on his third 318. I refused to re-build or install another 318. The tow truck came and towed it away. To this day I have no idea who or if the trck got a 318 or a 360. Apparently we weren't REALLY frtiends as we haven't spoken since then and that was almost 30 years ago.
You can add STP and some of the other "OIL" treatments" according to the Chemical Engineer in the family all any of them do is raise the viscocity of you oil by 10 points per bottle. So if you have some miles and are getting some blow by with 10-30 and you add STP or whatever, you are now running 40 weight and it might actually not blow by as badly. As for fuel econemy, can't happen and it defies all physics laws.
THere are some addatives that do work. Those designed with a speciic chemical to do a specific thing.
Freeze or gel the diesel in your tank and there is one that "If you are lucking" will disolve the parfine in the system and put it into suspension so it can burn. It also smokes like the USS Idqho laying down a smoke screen.
FUeled in Texas a few years back and headed home on I20 without thinking about it. At the top of the monutains in New Mexico my sone reported we had a heck of a head wind as we could only go 50mph in 5th gear. I looked at the overhed console and saw 23 degrees F and instantly thought oh Shucks or something like that. Stopped at the first truck stp and bought 4 gallons of fuel addative. By the time we got home we had managed to melt most of the parfine and it only required a fuel filter change and one injector. Whew.
There are other specific formulated for injectors etc that actually work if the problem isn't too bad. NOthing in a bottle will fix or cure a real problem or make your engine new or add 50 mpg.
There isn't any free lunch and the industry is NOT conspiring against you. On the other hand there are things that you can do for some of your hard earned cash that will help specific issues that the industry, car or oil don't do because they don't apply to every car and they aren't worth the added $20 per vehicle when costed across the entire fleet. TRust me, them boys that design and price this tuff use a real sharp pencil.
There are a few crashed military jets around this area. The Air Force has salvaged all they want. Each time I pass one I stp andspend an hour or so retrieving nuts and bolts off the engines etc. If the best we can buy is a grade 8 I have no idea what these wonderful stainless steel, with captured nuts and washers etc are graded at. I did ask a machinist once what they would cost for him to make . He looked at them and measured them and then took a guess of the materials used and said he thought he might be able to make them for $100 each!!! I suspect that in the official Air Force world the cost even more per unit. All I know is they work great on Dodge trucks and tractors. I also know that if Dodge actually used them to put their trucks together the MSRP would be $100,000 or so.
So maybe the addatives do something besides lighten ypour wallet , hence to total vehicle weight, thus increasing fuel economey and performance, but I wouldn't bet more than the price of the bottle of "stuff" on it.
I did appreciate the old boy I bought the 2003 Ram 3500 from with the Cummins that only used synthetic and changed it every 2500 miles religiously. Bubba's question/statement was "Good lord it couldn't have even been dirty at 2500 miles".
RTW
RWT