I played around with that on my last 2016 6.2 and noticed no real difference. For sure not enough to justify the higher pump prices. I stick with 87 octane nowadays.

 

Whatever the sticker on my vehicle recommends is what I run.

More important to fill up at high traffic stations, so you get fresh gas. For diesels, this is more important due to the seasonal fuel change.

For anything other than regular octane, high traffic stations are even more important. My VW pocket rocket does not like stale premium.

 

87 is the standard .. Fresh is best..

flex fuel if you must.. expect poor fuel mileage..

I tow heavy..

 

I tired the "flex fuel" once just for grins-great googly moogly-I barely got 6 mpg (pencil avg.) on the rural highways I drive.
High turnover rates, as mentioned, are important.
The other thing, more so in the summer, is try to fuel up in the mornings, as the fuel density is greater...it really only applies to aviation since most fuel facilities have their tanks above ground...that's a rabbit hole that would take it's own thread.
Generally I just run 89 which is the "low" end in my area with no ethanol (called Pure Gas). I pencil average 12-15mpg.

 

Thanks all. Appreciate the follow up

 

Towing through the hills in KY to SC, I switched to premium for a few tanks and did not see any improvement in mpg, performance, etc. so I always use the 87 octane. Played around with the E85 blends and the decrease in mpg was alway more than the cost savings so I do not use that either as it is more costly to burn it. Plus I did notice the performance decrease also with the E85 blends.

 

Some brands claim they add extra detergents and stuff to their 93 octane.

 

The marketing departments make lots of claims. But there is some legitimate marketing.

It is not so much that some claim to add something special to a certain octane, the real question is do they formulate their gasoline to meet the requirements of certain vehicle makers.

This requirement is marketed as "Top Tier." And many of the manufacturers who specify Top Tier do so for the highest-performance vehicles in the fleet; Those are the ones that in general will require premium gas.

But set that aside. If a gas station is Top Tier, then all gas octanes dispensed at the station meet the Top Tier requirement for that octane; and the most stringent specifications for vehicle manufacturers are met at the octane specified by the vehicle manufacturer. There simply is no need to pay for more octane or detergents than your make (or VW or Mercedes) requires.

Diesel? There is a Top Tier specification for it, but not all stations will carry it. If the station does carry it, then there will be a Top Tier sticker on the diesel pump.

A list of Top Tier brands is here:

Licensed Brands | Top Tier Gas

Frankly, if it is good enough for a Mercedes (or my turbo VW), it is good enough for my Ford. But there is no need to pay more for detergents in a higher octane than your maker calls for, the detergents in your Top Tier octane will be just fine.

I know it is good enough because Ford also specifies Top Tier for its fleet:

https://en.wikipedia.org/wiki/Top_Ti...rgent_Gasoline

 

Just watched this one

 

That Volkswagon TSI calls for 95 to 98 octane, but can run on regular with a loss of power.

The experiment in your video proves the engine can run on regular gas with a loss of power. It does not prove running on higher than specified octane results in more power or better economy. Or cleaner valves.

I have not seen you specifically make those claims, just aware others do. Really, not picking on you, just evaluating the video as an engineer.

 

Thanks all feel very comfortable then sticking with regular at good stations. I don’t cut corners on gas do for a few penny’s more stay away from the cheapo stations and get mostly at Costco or standard

 

My 6.2 runs best on whatever is cheapest.

 

Here it is, straight from the horse's mouth. This is a quote from chief engineer Mike Harrison on the "Ask the Engineer" thread back in '10. You will get some increased power with higher octane. In my opinion it's not worth the added cost, but it is there.

https://www.ford-trucks.com/forums/9...ml#post8833938

 

Top tier for mine.