NavyBlue2

Just filled up with 93 octane premium gas at Sam's Club at $2.15, one block away from my office.
My wife fills up with 93 octane premium gas at a large chain grocery store at $2.35, since it's right in front of our subdivision.
Both are not top tier gas, station manager at both says they get their gas from major name brand refineries nearby Houston area. They just don't add any additives to keep their cost low/lower.

We both also fill up at top tier Costco (or other top tier stations) maybe once a month or every other month.

GasBuddy app shows that most other top tier gas stations nearby are around $2.69 - $2.89 for premium.
So Figuring we're saving 54 - 74 cents/gal, or 25 - 34%, or $8 - $11 per fill up, times 4 times/month, times 4 cars = $128 - $176 savings per month, or $1536 - $2112 per year.

So question is, if we regularly pump with non top tier gas, what/which gas additive, to replace the top tier gas additives, should we add to our tank once in a while to keep it clean?

Glennm27

Techron by Chevron

NavyBlue2

Yes, that 10 oz bottle costs $5
It says: It treats up to 15 gallons and is recommended every 3,000 miles or at your oil change.

So is that almost the same formula as they put into top tier gas at Chevron gas station?
Same concentration?

NSC5

The extra cleaning additive required to be a top tier licensed station primarily helps port fuel injected (or older carburetor fed) engines because the intake valve deposits that Techron and similar additives are designed to prevent aren't exposed to the fuel/air mixture in a direct injection engine. I use mostly Shell 93 (which is top tier) in my Z06 but prior to winter storage it gets several tanks of HyVee 91 octane which is not top tier but it is non-ethanol which is more important to me than having extra additives of dubious value in a direct injected engine.

If I had a choice between 93 octane E10 top tier and pure gas 93 octane non-top tier I would take the pure gas in an instant. Every decent quality modern fuel has a good detergent package and much of top tier is a marketing effort designed to allow differential pricing of a pure commodity product.

C82LT

Techron or Gumout Regane. I typically use Regane since it’s a little less expensive but both have decent amounts of PEA.

LDB

You have to make your own decisions on cost/benefit tradeoffs, so I’m not telling you what to do. I’m simply going to give you some engine cleanliness facts. First, I’ll cover port injected engines because I’m more familiar with them. Direct injection was just coming in when I retired, so I haven’t seen nearly as much data on them. With port injected engines, if you disassemble and inspect the engines after 50,000 miles you can clearly tell the difference between top tier and cheap gas. Engines run on cheap gas were not filthy, but they were clearly dirtier than top tier engines. Intake valve stems and ports were the most obvious difference, but there was also noticeable difference in piston crowns, spark plugs, and injectors. The extra cleanliness is what the auto companies were after when they developed the top tier standards to reduce their warranty costs.

Tests with cheapo gas plus occasional heavy doses of additives helped a little bit, but did not get the engines back to being as clean as top tier engines. Running several tanks of top tier gas (meaning a dozen or more in a row) through a dirty engine still didn’t get you back as clean as running top tier from the start, but it was better than occasional heavy doses of additive. If you draw an analogy to a clothes washing machine, it makes sense. If you use half a dose of detergent most of the time, and a double dose every 5th or 6th time, you wouldn’t expect the clothes to be as clean as they would be with the proper dose all the time. There is such a thing as too much detergent, because the detergent itself leaves a bit of residue as it evaporates/burns in an engine (or simply doesn’t rinse completely out in the clothes washing analogy).

Some folks say top tier no longer matter with direct injection since the intake ports and valve stems are not in the mainstream of washing by the incoming gas. That’s partially true, but you still have nontrivial cleanliness issues with injectors, spark plugs, and piston crowns, and the gas still fully contacts those. And even with intake port & valve, some direct injection engines orient the injectors and pulse a bit of fuel prior to intake valve closing to get at least some washing. I do not know if GM direct injection engines do that. But GM does continue to recommend top tier even with direct injection engines, so they obviously think it is still important.

As to the ethanol top tier versus non top tier ethanol free, I disagree with NSC5 and would go with top tier even in a direct injection engine. While I don’t like ethanol because of its poor economics, it doesn’t have performance drawbacks beyond the 3-5% mileage reduction, so why should I accept an engine cleanliness penalty for no return benefit? If the answer to that is because of its poor economics, the poor economics don’t come out of my wallet at the gas station. Ethanol gas is usually cheaper there. The poor economics are hidden in the regulations that force it in, and that’s a political issue outside my control since for different reasons, both parties support it.

dvilin

I use 93 octane where ever top tier non top tier no harm no foul never add anything all good.

Globeman

From the 2016 Owner's manual;


I use only only Top Tier gas but I still dump in a bottle of Techron every year when the C7 goes into hibernation. I wouldn't be surprised if the official GM approved additive is Techron.

JNess

I only gas up at Quik Trips or Racetrack which are both top tier. Interestingly, Kroger also has top tier around here, in DFW.

Z0HS1CK

Sorry to bump this thread but anyone has used this?


I know about good fuel cleaner with PEA to clean the injectors etc but there is nothing for the intake valves in a DI engine.

But i was wondering if anyone has used this in their C7? Or particularly in a Z? As i'm worried about the blower. I have 7k miles now so the worry is starting on the carbon buildup

C82LT

I use Gumout Regane. I just also recently started using Techron since BMW uses it in repackaged containers. I haven’t used either on the Vette yet.

Patman

I currently use Gumout Regane Complete fuel system cleaner once a year on all of my cars, it's only about $4 at Walmart and has a decent dose of PEA in it.

However, when I get my C7 I am planning on running nothing but Top Tier gas in it at all times. Even when I'm on a road trip I plan on bringing a printout of all the gas stations that have Top Tier and making sure I only stop at those ones. If I start using Top Tier from day one I figure I will never need to add anything else to the fuel.

rrsperry

Ok, a few misconceptions. I was a terminal manager for an oil company. (Hess Oil).

Anyway, ALL gas sold in the US has additives. All of them must meet minimum Federal specifications. When the delivery truck load the gas foe ANY station, a basic additive is injected as it loads.

Top Teir gas uses a better additive package that costs about 3 times what the basic package costs. Every Top Tier station additive is about the same stuff no matter what brand. The only one that was different was the Sunoco 94. It got a proprietary package, and we, (actually Sunoco paid us to do it) had to build a dedicated loading rack for them. But they are all getting the package from the same company.

Now with a DI engine, you start running into some issues. Particularly, you aren't washing the intake valves, but seeing as Chevy has millions of miles on the LT engines, I'm not worrying about it.