Preventing the LSPI Super Knock Grenade in Turbo TDGI Engines

LSPI Super-Knock Will Soon Damage Newer Turbocharged T-GDI Engines in Your Neighborhood, Maybe In Your Driveway

How do you protect your 2013+ turbocharged gas engine from “super-knock”, or Low Speed Pre-Ignition (LSPI) damage, which is caused by normal driving?

Vehicle manufacturers know LSPI damage in new T-GDI (turbocharged gas direct injection) engines is a serious risk and have temporarily programmed vehicle software to “detune” the engine below the intended level of engine horsepower and fuel economy, in order to avoid LSPI-inducing conditions. Doing so, however, limits fuel efficiency.  The SAE, API, ASTM and OEM’s will soon issue a new oil grade with new tests to prove oils prevent LSPI (as it turns out, it’s one of the most difficult tasks that engine oils have ever been called upon to do).

Soon afterward, to extract maximum efficiency from their advanced power plants, OEMs will implement software updates (expected in 2019) to unleash more power and improved fuel economy, along with much higher susceptibility to LSPI. New cars sold after this will have the updates, and vehicles serviced by dealers will get the updates.  But I don’t know that we can control this as consumers, or even that we will always know.  It’s possible that some of these updates may happen wirelessly overnight, as your vehicle sits in your garage or driveway.

We are pleased with how AMSOIL has worked hard to fully prepare for these future OEM updates, protecting their customers’ cars, trucks and fleets by reformulating their engine oils long before new testing standards are finalized.  Proving it can fully protect turbocharged direct-injected engines, AMSOIL entire new line of synthetic engine oils have all achieved 100 percent protection against LSPI in the engine test required by the GM dexos1®Gen 2 specification.

We are pleased with how AMSOIL has worked hard to fully prepare for these future OEM updates, protecting their car, truck and fleet customers by reformulating their product line long before new testing standards are finalized.  Proving it can protect turbocharged direct-injected engines, AMSOIL entire new line of synthetic engine oils have all achieved 100 percent protection against LSPI in the engine test required by the GM dexos1®Gen 2 specification. (AMSOIL protection goes further than that, too, with important protections that other oil companies don’t consider. We’ll explain.)

dexos1® oils vs. dexos1®Gen 2 oils

Please know that hundreds of oils have passed the older dexos1®Gen 1, often just shown as dexos1® on labels.  Beware, because dexos1® oils don’t come anywhere near passing dexos1®Gen 2.  If it does not say “Gen 2”, it must NOT be used in a T-GDI engine.

What does it really mean to pass dexos1®Gen 2 testing?  Gen 2 tests for very low turbo deposits, PLUS low LSPI occurrence. While several dozen oils are already certified to GM’s spec, ahead of an official industry standard test, dexos1®Gen 2 certification does not require 100% LSPI protection.  Few people understand what this means, but we think this point will eventually prove to be crucial for vehicle owners.  Here’s why:

  1. Oils can have a specified number of LSPI events and STILL pass GM dexos1®Gen 2.
  2. Other than test data provided by AMSOIL, consumers will NOT be told how well an oil perform:  concealing lubrication performance in the industry’s standardized testing is how petroleum companies keep consumers from understanding the need and value of true constructed-molecular-design synthetic lubricants.
  3. Because the piston-stresses of LSPI events can be severely high, there is potential for occasional LSPI events to create cumulative microstructure damage in the pistons as mileage gets higher, leading to sudden fatigue-fracture piston failure.

Premature Timing Chain Wear in T-GDI Engines

Still another growing T-GDI issue is rapid timing chain wear on some of these engines.  In fact, a Ford technical service bulletin (#14-0194) acknowledges timing chain wear as a problem in certain vehicles equipped with its popular 3.5L EcoBoost® engine.  (However, the bulletin does not reveal that switching to AMSOIL Signature Series synthetic engine oils will eliminate this wear problem.)  The wear due to occurring due to oil soot generation levels which can run on the level of older diesel engines, soot content which most oil formulations besides AMSOIL have not protected for because these engines aren’t diesels, and because even the latest oil specs have not addressed it.  What this also means is that the size of diamond-hard agglomerated soot particles in many oils will eventually be recognized to be causing more T-GDI accelerated wear areas than just timing chains!

For all these reasons, for best protection against soot wear and accumulated LSPI fatigue failures, we recommend using only AMSOIL engine oils, and to NEVER add any oil additive to ANY engine oil in TGDI turbo’d engines, and to regularly use a high-performance fuel additive like AMSOIL P.I.

That’s the short summary.  But we need to dig into the crucial details, and sobering facts, before you really wish you had known more.

Why is LSPI such a big deal, when engine knock has been around since at least the 1960’s, mainly in hot-rod tuning which included advancing the ignition timing?  Because it’s different and worse, and it may already be sitting in your driveway.

The “super-knock” slang for LSPI hints at how its’ combination of new technologies mainstreams engine knock into commuter driving, and increases the damage severity.  The potential exists for ordinary drivers to accelerate from a stop-light to get in the correct lane, and find themselves paying the tow-truck a fraction of the costs they will soon face to repair or replace their engin

LSPI is somewhat like a rattlesnake with a missing rattle.  It’s as if you can go through your normal day unsuspecting of any risk, and suddenly with no warning like a rattlesnake bite, find yourself in a bad situation:  you don’t know how much venom was injected, but the painful news seems to grow worse by the hour.  But, a better analogy is a hand grenade.

Would you throw a grenade in your engine air intake and then start the engine?

Of course not!  And that’s why you don’t want LSPI – because it is an uncontrolled explosion, whose power to shred your engine comes from the worst possible combination of circumstances.

It’s agreed that under normal conditions expected by OEM engineers, LSPI should rarely, if ever, occur with adequate power to cause damage.  That’s the plan.  However, those “normal expected conditions” rely on a lot of sophisticated interactive engineering to create two new, novel achievements: that the combustion area will stay clean and free of deposits, and that both the fuel quality and the engine oil formulation will do their part to prevent deposits and small residue areas of unburned fuel.  And according to Lubes and Greases in early 2018, the industry still doesn’t understand LSPI yet: although they know some things that help, and other things that make it worse, they don’t understand why.  See any risk there?

To understand the importance of these questions and the magnitude of potential problems, consider that T-GDI engines are now dominant throughout nearly every OEM lineup as either the primary or an optional engine. (Think Ford, GM, Chrysler, Toyota, Nissan… just name every OEM.)  Here’s one typical example that will help you understand LSPI severity: Green Car Congress reports that BorgWarner’s regulated two-stage (R2S) turbocharging technology is now improving the performance and fuel economy of Ford’s new 2.0-liter TDCi diesel engine, the first Ford engine for passenger cars equipped with a two-stage turbocharging system. The sequential bi-turbo setup boosts the lightweight 2.0 L engine to an amazing 207 hp output that 15 years ago took a 3.0 L engine that weighed over twice as much.  Yet in the 2.0L marketplace, 207 hp is a tame power level. The 180 hp 1.8 L in the 2002 Audi TT also had a factory-tuned version that put out 225 hp.


As the accelerator pedal is pushed, Direct Injection controls enable dynamically advancing the ignition spark timing and modifying the timing, volume and rate of gas injected, and a turbocharger boosts the pressure of fuel & air going into the cylinder, but pre-ignition explodes the fuel before spark-plug activation while the piston is still rising in compression, and Low Speed rpm puts the highest pre-ignition cylinder pressure near top-dead-center (TDC) where the piston can’t move quickly enough to lower the pressure spike.  The pressure spike is higher because more fuel was injected, and the ignition front is larger and much faster.  There are still more compounding factors, such as thinner, lighter pistons.  So LSPI is a combined worst-case situation which is the “perfect storm” recipe for engine damage, not only because the force applied to the piston and piston rings can be several times higher than they are designed to handle, but because broken piston piston pieces can bounce around the combustion chamber and out the exhaust port – into the turbocharger where the impact with multiple turbo-blades spinning at 10,000 to 250,000 rpm can send high-velocity turbo blades through the engine compartment and even completely through the car hood.

Of course that “cannot happen” because there are sensors and control logic to minimize the severity of what could happen, and turbochargers almost never explode outside of dyno/track race-tuning.  All true.  But this is the point: the power is there, the mechanisms are there, and engineers, sensors, and control logic cannot always predict and compensate for every situation without error.  However much uncertainty and risk lives in the combined synergic details of a particular turbo GDI engine model year and software revision is unknown. Let’s all hope the bigger problems are not under YOUR hood.

“Super-knock” has serious damage potential even when systems minimize or silence the catastrophic drama.  In less than two seconds, LSPI could scrap an engine block, heads, pistons, and one or two turbochargers.  Seconds later in a worst-case scenario that every OEM hopes cannot happen, the aftermath could even force you to flee your burning car.

AMSOIL protects turbochargers 3 to 4 times better than Royal Purple and Mobil 1, and had ZERO LSPI events in GM’s dexos1®Gen 2, the auto-industry’s best available engine test as of Sept 2018.

No, this is definitely NOT a situation that OEM engine chiefs want to be in.  But this is the corner where the mandated federal fuel-economy regulations have pushed OEM’s.  The required engineering intensity is on a level that used to exist only on the race track, the runway, or the launch pad. But the engine oil, the fuel, and the vehicle maintenance are all important interactive factors which can only be tightly controlled by a professional racing team.

Why Oil Additives are a VERY Bad Idea in the Brave New World of LSPI “Super-Knock”

After OEM installation of new software, engines running with a motor oil that is not formulated to combat LSPI will be at great risk of damage, and it can be severe.  The OEM’s and industry drivetrain engineers all agree on that fact.  But they also agree that engine oils which are developed to prevent LSPI will enable controlling and minimizing LSPI occurrence.

HOWEVER, one important risk factor which is getting little attention is aftermarket engine-oil additives.  At DMT Technical, we expect that many oil additives will imbalance the finely-tuned oil formulations, enabling LSPI either immediately or gradually as the engine oil ages before the next oil change, and creating a wave of super-knock engine rebuilds which WILL NOT be covered under warranty.  Vehicle owners who learn this the hard way will be shocked at the cost of engine repair or replacement.

Best Recommendations of DMT Technical and UltimateSyntheticOil to Prevent LSPI Damage

These three recommendations minimize the risks of LSPI damage in a turbocharged T-GDI engine:

  1. Use AMSOIL engine oils because as mentioned above, they have been rigorously developed to prevent LSPI.  In the best currently available industry testing (GM dexos1®Gen 2 engine test), all AMSOIL engine oils for recent gasoline engines didn’t simply “pass”, but had ZERO occurrences of LSPI and protected turbocharger performance at the highest levels.  And – shocking fact – AMSOIL is the only oil company who warranties their oil performance against damage.  Here’s where to get the best oil recommendations for your specific vehicle.
  2. DO NOT USE ANY engine oil additive.  For more info on the BEST way to get maximum engine protection, here’s the single best overview of oil additives – and many people agree.
  3. Use a very good fuel additive.  We recommend the extensively tested AMSOIL P.I. (performance improver), not only for its ability to effectively clean the entire fuel system, injectors, combustion chamber, pistons and piston rings whose cleanliness is important to avoid LSPI, but also for its easy use, low cost, and demonstrated fuel-economy improvements.

Uncertain about AMSOIL?  No problem, because we’ve done years of work to help you with that!  Here we pit Michael Phelps against AMSOIL’s performance, and explain why AMSOIL’s superiority is more impressive, more trustworthy and more highly credentialed than even Michael Phelps with more Olympic Gold Medals than any athlete in history. (Yes, really.)

Our Opinion of T-GDI Impact in the Oppressively Regulated Automotive Market

Turbocharged GDI engines have been coming into the market fast beginning about 2013, spanning 1.0 L, 1.4 L, 1.6 L, 1.8 L, 2.0 L, 2.4 L, 2.5 L, 2.7 L, 2.8 L, 3.0 L, and 3.2 L – to name a few. These are in most cases completely new engine designs, fielded not only by Hyundai, Kia, Honda, Toyota, Nissan and Mitsubishi, but also by GM, Ford, Chrysler, Fiat, Porsche, Mercedes Benz, Audi, etc.  In some of the latest models they are coupled with 11-speed automatic transmissions (I wish they were kidding). Increasingly, the newest models use two turbos to maximize performance and fuel economy.  WHY?

Our studied analysis is that OEM’s have been given no choice.  They are all in the same global-market “boat”, hijacked in the same central-planning totalitarian coercion that has often destroyed nations and threatened the globe more than once.  No OEM wants to protest about durability concerns when their honesty could backfire and torpedo their sales in the face of their traditional competitors or the fast-rising electric vehicle (EV) market.  When taking this situation as a whole, analytical, technically-savvy consumers and engineers are bound to grow concerned about the medium and long-term cost-of-ownership viability and warranty viability of these engines.

Is this just alarmist “sky is falling” worry?  Maybe, but don’t bet on it.  The dark reality is that the totalitarian fuel economy mandates are forcing new vehicles to have intensively complex engineering requirements with loads of new technologies, rushed to market without adequate time to fully develop or understand the interactions of multiple radical changes in multiple system designs and technologies which are all being combined together for the first time.  To be clear: those CAFE mpg mandates carry crippling financial penalties which force the situation to get worse with every new model year.

To illustrate, one of the most effective design development tools in automotive engineering was displayed in the 2000’s era by Ford’s “D-FMEA with Robust Linkages” (Design Failure Mode Effects Analysis).  Ford found that by evaluating the interaction of every engineered sub-system with the content and design of every connected or adjacent system, they could make vast improvements in 1st-model-year vehicle quality and durability.  But in the mandated new climate, successfully retaining Robust Linkage analysis is unlikely. It will tend to become an OEM culture-casualty in the engineering wars that will ultimately prove very costly to both consumers and OEM’s.

Take this 2015 F150 truck with 2.7 L EcoBoost video story for example, that was purchased because it was cheaper than the 5.0 L engine (at the dealer) and got better fuel economy, has a graphite engine block, a plastic composite oil pan (adds strength and cuts weight) & lots of other new cool tech.  The owner reports that at 4,000 miles it had an oil leak, from the oil pan bolts, which the dealer replaced.  A thousand miles later, the same problem, the same fix again. (The forums know about the problems, but not the dealer?)  It towed great in the mountains, but then needed a fourth oil pan.

Then while towing again, something happened, the oil pressure dropped to zero. Added oil, drove it back to the Ford dealership, they wanted to run an oil consumption test.  Limp mode engaged, and it turned out that a chunk of exhaust valve had broken off.  [“Danger, danger Will Robinson!”]  Naturally, it scored the cylinder wall (and did other damage).  So they replaced the engine.   And it ran flawlessly for the next 10k miles, with some towing in Colorado. But the owner is concerned about keeping the truck past the 60k mile warranty.

This House Committee Report detailed the ugly saga of OEM’s new CAFE minefield, which taxpayers fund out-of-pocket at dealerships and repair shops.

It sounds as if the dealer made no mention of LSPI, and did not detail the full extent of the damage such as to the piston(s) and turbocharger.  But it’s likely that LSPI caused the damage, and essentially totaled the engine.

I’m not picking on Ford but using them as an example, because these issues will not be unique to Ford – they are unique to turbocharged gas direct-injection engines.  Do I think the OEM’s will “iron out” the T-GDI wrinkles?  Yes, but no, because almost every year OEM’s and their supply-chain are forced into another bunch of not-quite-fully-proven tech change combinations, all to drive average CAFE mpg upward fast enough to stay out of bankruptcy.

I see nothing that suggests it will get better, and the only glimmer of hope is that President Trump’s administration might decide to tackle this crippling situation, and might be successful.  Until the auto industry is rescued from this corruption which appears deliberately conceived and targeted to destroy the automotive industry, I expect the reality of the cool new technologies rolling off dealer lots will only get worse for everyone.

For those unaware, the North American auto industry was illegally hijacked by the machinations of the prior regimes “car tzar”  and coerced to sign up to what one congressman referred to as a slow-motion-suicide pact.  A congressional sub-committee staff investigative report (pdf link at right) which detailed the ugly realities was a significant factor in why I decided to not only leave OEM headquarters, but get out of auto industry design & manufacturing.


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