2019 Silverado - Fuel Additives

[lord.kinbote]

Anyone use fuel additives on their trucks - if so, which one and how often?  Owners manual indicates at every oil change if not using top tier detergent gasoline.  I fill up with 93 octane, so not sure if needed.  Thanks in advance for the insight.

[Mountain boy]

Unless you have a 6.2  93 is not needed, Sea Foam is a good additive, GM actually sells one too. Cheveron makes a good one. I run 100% gasoline about half the time so don’t worry about it much.

 

A recent AAA report found that American motorists wasted $2.1 billion dollars in the last year buying premium gasoline for engines designed to run on regular gas.

The reasons why are likely due to the following misconceptions about premium gas:

• Contains higher energy content (increasing power and fuel economy)
• Formulated with higher-quality additives (increasing engine cleanliness)

 

What is Premium Gas?

When motorists see premium 91-octane gas at the pump, they may assume it contains higher energy content compared to regular 87-octane gas. After all, “high-octane” is often synonymous with increased power and performance. The 91-octane gas should, they think, provide improved fuel economy and power.

In fact, octane has nothing to do with energy content or quality – it’s a measurement of the gasoline’s ability to resist engine knock. Higher octane denotes greater knock control.

What is Engine Knock?

On an engine’s intake stroke, the piston travels down the cylinder, allowing air/fuel to fill the available space. Assume the cylinder holds 900cc when the piston is at bottom dead center. The piston then travels up the cylinder, compressing the fuel/air in preparation for combustion. Assume cylinder volume is reduced to 100cc when the piston is at top dead center. The relationship between the two volumes is known as the compression ratio. In this case, 900:100 is reduced to 9:1. The compression ratio indicates cylinder pressure, and more pressure equals more power and greater efficiency. That’s why high-performance cars and heavy-duty diesels typically have higher compression ratios than standard cars or trucks. 

While higher compression seems like all up-side, it can invite negative consequences. Compression heats the fuel/air mixture, allowing it to burn more efficiently. If compressed too much, gasoline can spontaneously ignite, causing uncontrolled and early ignition. This leads to a knocking or pinging sound, robs the engine of power and can lead to engine damage. Typically, the engine’s computer will detect engine knock and adjust timing and the air/fuel ratio accordingly. Although this protects the engine from damage, it can substantially reduce engine performance and efficiency. 

Most high-compression gas engines require use of premium gas to better resist engine knock and prevent the computer from detuning the engine to protect against knock-related damage. Using premium gas in a clean, mechanically sound engine not designed to use it, though, provides no benefit.

In engines with carbon buildup on pistons or in the combustion chamber, however, premium gas can provide some benefit. Deposits can reduce cylinder volume at top dead center, effectively increasing the compression ratio. This alone can lead to engine knock. The deposits can also become hot spots that preignite the mixture, leading to engine knock.

In these cases, a higher octane fuel helps resist engine knock and allows the engine to operate closer to its normal conditions rather than detuning to prevent engine knock.

For best performance, use the fuel recommended in your vehicle owner’s manual.  

Higher Octane Doesn’t Mean Higher Quality

The other popular misconception is that premium gas contains a higher concentration of cleaning agents and other performance-improving additives.

While many formulators market a high-quality premium gasoline, such as Shell* V-Power* Nitro+ or ExxonMobil* Synergy*, the premium gasoline at your local filling station may not be formulated to improve performance in any aspect other than octane rating. Quality can vary from brand to brand and station to station.

AMSOIL P.i.® and AMSOIL Quickshot® are excellent in these situations. They provide outstanding detergency to help clean dirty injectors and carburetors for maximum fuel economy and operability.

[newdude]

Per the manual, GM only recommends their own additive if TopTier gas can't be found:

 

Quote

 

Fuel Additives

 

TOP TIER Detergent Gasoline is highly recommended for use with your vehicle. If your country does not have TOP TIER Detergent Gasoline, add ACDelco Fuel System Treatment Plus−Gasoline to the vehicle’s gasoline fuel tank at every oil change or 15 000 km (9,000 mi), whichever occurs first. TOP TIER Detergent Gasoline and ACDelco Fuel System Treatment Plus−Gasoline will help keep your vehicle’s engine fuel deposit free and performing optimally.

 

 

[Ozer]

I use Techron and found that this is the only one that solved my misfire problem, after plugs, wires and coils didnt fix it. Assuming it was an injector issue.

I use it every once in a while.

[Sin City Trail Boss]

I use Techron, but the concentrated stuff. I haven't been able to find it at locals stores, so I order it off Amazon. Really great stuff.

[Black02Silverado]

Best thing to use is Top Tier and use a station that has a high turn over.  That way the fuel is always fresh. 

[Grumpy Bear]

1 hour ago, Ozer said:

I use Techron and found that this is the only one that solved my misfire problem, after plugs, wires and coils didnt fix it. Assuming it was an injector issue.

I use it every once in a while.

 Techron is the additive package used in their own fuel. I treat two cans to 25 gallons every 5K. I no longer live in a Chevron market. Great stuff. 

[txab]

GM uses a re-labeled Techron in their service

[Grumpy Bear]

5 hours ago, txab said:

GM uses a re-labeled Techron in their service

Well how about that! 

[MacLaren]

I use Exxon unless I see Mobil 1

Either I like a lot.

[NeverCold]

Use Top Tier gas.  I actually use Gumout All in one, it is also a PEA based cleaner like Techron.  I use it a tank or two before an oil change (so 2x a year).  

 

Edit: that's in other vehicles, I'm only 500 miles into my current Chevy but that's my plan