Smart Solution or Snake Oil?

Part 2 - The Bad.

By P Sanchez
Last time, we discussed tire sealants and radiator sealants that offered quick solutions in an emergency. But whenever a company claims that they have found a way to conveniently bottle the expert services of a mechanic, consumers should always take such an incredible claim with caution.

Sometimes the product is more of a hit-or-miss affair. Other times the product only works in very specific scenarios but the company’s marketing efforts have been a little too liberal in showcasing the product's application. At worst, they rely on the placebo effect and are in general, a big waste of money. We’ll discuss some of these “baddies” and see what most experts think.

---

Bad or Just Misunderstood?

For practical manufacturing reasons, the engine case is not carved out of a single block of metal but much like the rest of the vehicle – is an assembly of parts. This means you’ll have seams all around, points where internal fluid could leak out. To prevent this, gaskets and seals made of pliable materials are sandwiched in the seams to provide a strong and airtight fit. However, the extreme operating environment of an engine degrade these seals over time. This is an inevitable course and just a question of when.

Of course, the permanent solution to any engine problem is taking it to a professional car repair service. Depending on where the leak is, the engine job may involve taking out the engine from the car, dismantling it and replacing the seals. As you can imagine, an engine rebuild is an expensive process that may prove more costly than the current day value of your old car. Most experts recommend either disposing your vehicle or if the leak is not bad enough, you can just top-up on engine oil every so often and live with the handicap.

Mechanics also recommend mixing in an additive that raises the viscosity of the oil (Lucas Oil comes to mind) or trying a thicker grade oil. The idea is that the thicker oil will permeate less through the cracks and crevices. A few others will recommend using additives that “recondition” or swell the seals in the hope of closing the cracks that have developed (engine oil formulated for high-mileage engines is just one example). Since the price of these additives or replacement fluids could cost as much the oil you’ll be losing from the leakage, most mechanics will say they are at least worth the shot. Just make sure that your engine will be able to run on higher viscosity oil. A bit of warning: most modern gasoline engines are designed to run only on thinner oils for efficiency purposes and more importantly, hydraulic considerations. Do your research first and get advice from your mechanic.

To Clog Or Declog.

If you’re one of those who are particularly fussy about the cleanliness of your car, not just the exterior look and the interior but everywhere – including the engine bay, undercarriage, and every nook and cranny that nobody will bother to look – then you’re probably worried about carbon build-up in the engine. Who wouldn’t be, right? Just seeing the build-up of soot around the insides your tailpipe will conjure images of crusty engine valves and blackened cylinder walls. The thought alone sends shivers up any obsessive-compulsive’s spine.

Ok, so carbon build-up can really be a thing. If you’ve put on over two hundred thousand miles on your car, the insides of your engine will certainly be a lot less pristine than the day you first bought it. But should you worry about carbon build-up?

Companies that produce engine care products like aftermarket fuel additives would say so. They forward that carbon build-up is one of the leading causes of lowered inefficiency with engine age, particularly in causing clogging of fuel injectors. New injectors put out a fine spray of fuel in the cylinders, helping create a more homogeneous fuel-air mix that combusts more thoroughly. Older injectors are found to operate inconsistently with fluctuating fuel pressure and often squirting fuel rather than spraying, leading to poor fuel economy and performance. Is carbon build-up to blame? And do additives do what they’re supposed to do?

I say fuel additives work and they work in a lot of ways. They can deter corrosion, promote even burning of fuel and helps prevent carbon build-up. That’s why a good percentage of the fuel you get from gas stations already have additives mixed in. Moreover, liquid fuel like gasoline is itself a good solvent. In most cases, just sticking to good fuel is enough to keep excessive carbon build-up at bay.

But how about all those product reviews (like this one) “proving” that aftermarket fuel additives work, even comparing horsepower readouts before and after treatment, with the latter readings showing significant improvements? Assuming that these tests were truly independent, notice that most of the vehicles getting benefits have older direct fuel injected engines.

As opposed to the more common port injection where fuel is sprayed in the channel behind the intake valve, direct injection sprays fuel directly in the cylinders. This design promotes better thermal efficiency. But unlike port injection where the injector is protected from combustion behind the closed intake valve, direct injectors are exposed to combusting gases, making them vulnerable to carbon clogging. Check a comparative diagram here. In short, only older direct injection engines stand to benefit from additional fuel additives, especially if the fuel delivery issue is with clogged injectors and not other possible issues like with the fuel pump, solenoids, air and oxygen sensors, etc.

The takeaway? Benefiting from fuel additives vary very widely and you have to have a specific kind of engine with a specific issue to make the most of the product. The only way to know for sure that you have clogged injectors (or excessive carbon build-up for that matter) is for a mechanic to perform a high-end OBD scan, a visual inspection of your engine internals with a boroscope, as well as pressure-testing your fuel system. They also have equipment that can unclog injectors more thoroughly than any additive can. But if you rather take a chance with additives, you can. Just make sure to temper your expectations.

Next Time

We take on The Ugly. “Solutions” in a bottle that could more harm than good.

By the way, do you standby the benefits of additives? Or is it a total waste of money? Feel free to leave comments below.