SamDoe1

You're right that this is just another data point in the sea of the internet but you sent off different injectors from two different engine designs with different tuning and two different cars that were driven differently by different people and with different gas from different stations from different parts of the country...and want to come to some sort of conclusion on this?

Sure, but more is not always better. The more additives you add, the less amount of fuel per injection you get. If it takes a gallon of paint to paint a given wall completely, what value is there in painting 5 gallons on it? Seems like a pretty big waste.

Again, more is not always better. If you go to a reputable gas station that sells "Top Tier" certified gas, you should be just fine. "Top Tier" is a spec for detergent volume that is apparently the right amount of cleaning materials to make an engine work. There are a lot of stations that sell this stuff and we've put it in my wife's Accord for the past 80k miles without any issues. Granted you'd never know if there was an issue until there was...but still. The S2000 gets gas from Costco and so does the Jeep. Seems to work just fine.

Yes I know this is yet another data point in the vast sea of the internet but at least it's some sort of actual spec to compare against.

If the car says "Required", then you have to do it. If the car says "Recommended", then you should probably just do it anyway as this is mostly an emergency type of thing. If the car doesn't say anything, then don't bother with premium gas as long as you get good gas. "Premium" as a statement is a marketing ploy. The biggest difference is the resistance to detonation and that's really the only reason to use the stuff.

No one knows and there are no real standards to define this. The EPA requirements for detergents are pretty low and haven't really changed over the years. In this day and age, and in a bigger city, I don't think it really matters. I just go for "Top Tier" and call it good.

Of course. This is how they get the best performance but it isn't required to run the engine.

SamDoe1

Sam's club has never used Top Tier gas. I've had actual issues with their gas causing clogged injectors and carbon build up when I used it in my old Accord years ago. I haven't used it since and don't plan on it but it may have changed in recent years.

At the end of the day, it's the Walmart of gas...so...yeah. Costco gas IS top tier certified and I've never had an issue with it.

horseshoez

iTrader: (2)

@SamDoe1, unless you're talking about an engine which features direct injection, how do you explain and qualify "carbon buildup"?

SamDoe1

Clogged injectors. Crud in the ports below where the injectors spray. Build up on the valve springs. I never pulled the head or valves so I have no idea about that.

I guess I'm not entirely sure about if it's carbon build up but definitely crud in there.

horseshoez

iTrader: (2)

Ahhh, you not ever having never pulled a head I understand. I've pulled hundreds of heads and here are a few comments in context:

• Fuel of any type will have no affect on valve springs, that's the job of the oil to keep clean.
• I have never once seen a valve, injector or the port area in the spray zone which had even a single spec of dirt or carbon, or anything else for that matter except shiny metal on a healthy head. One exception here, if an intake valve is burned then all bets are off, but once again, this is a very different issue.
• The fact is, the fuel companies and the auto manufacturers are in almost constant communication regarding which additives need to be in fuel to keep the fuel system of modern cars in top condition for the life of the engine. To be quite honest, I don't think you can buy gasoline anywhere in the U.S. or Canada where the fuel isn't sufficiently supplied with additives.

Mr Hyde

Just to clarify, top tier standards just have minimum requirements across all grades of gasoline including regular. That's important for a car running regular gasoline, but for a car running premium, just because a brand isn't top tier, that doesn't mean that their premium blend doesn't meet or most likely exceed top tier standards.

svtmike

I read this all the time, and understand that it's possible. But how do you know without a certification like Top Tier that the pump you just rolled up to will dispense a premium blend that meets the Top Tier standards?

SamDoe1

I think that last bit is the most important. Provided you get gas from a reputable place, I think you'll be just fine regardless of grade of fuel. "Premium" is an octane number above all else. If you don't need it, then don't buy it.

Right. But without the tag, you really have no idea what's in the premium blend anyway let alone the regular.

Mr Hyde

For the most part, now, that is really only an issue with the no name brands.

Can't think of any name brand gasolines who's premium blend who didn't when I read about this years ago, but i did remember initially that Chevron, and Shell were first, and others like Mobil, and BP took awhile to catch up. Their premium blends were fine, but their regular blends only met EPA standards which weren't high enough for top tier status. It's been awhile since I have owned a car that hasn't required premium,so I've always been covered, and never go to those mom and pop gasoline stations.

I just looked it up. and that is pretty much the case now. I have a lot of Sunoco's here in NY, and they just made the cut this year for top tier status which is really surprising. Their premium blends were fine, and I used them routinely a few years ago when I lived near one, but really surprised they weren't until recently for their regular blends.

Theres a complete list here to check whichever stations are near you.
https://en.wikipedia.org/wiki/Top_Ti...rgent_Gasoline