Gas ?

killramos · August 2, 2019

It’s the other way around, 93 is the base case for the engine. 87 is a limp mode type case where the engine functions but at reduced power and fuel economy.

87 compatibility is there in case you area tough spot in the middle of nowhere At a shitty gas station that doesn’t offer premium and you need to fill up to get to a station that offers the correct fuel for your vehicle.

The manual makes this very clear, you should always use the highest rating the manufacturer lists in the manual. Regardless of the wording this is the fuel the engine was designed to use.

RUSSH · August 2, 2019

87 on my current 5.3.

Always ran 93 on my 6.2's

aseibel · August 2, 2019

21 minutes ago, killramos said:

It’s the other way around, 93 is the base case for the engine. 87 is a limp mode type case where the engine functions but at reduced power and fuel economy.

87 compatibility is there in case you area tough spot in the middle of nowhere At a shitty gas station that doesn’t offer premium and you need to fill up to get to a station that offers the correct fuel for your vehicle.

The manual makes this very clear, you should always use the highest rating the manufacturer lists in the manual. Regardless of the wording this is the fuel the engine was designed to use.

I'm clearly not going to change your mind. Nor am I trying to. There is plenty of commentary on this topic, both on this forum and across the internet. You buy whatever gas makes you happy. I think you are greatly exaggerating the effects of using 87. I bet you wouldn't notice the difference except on a timed track run.

I'm simply answering the OP's question about whether there is an economic advantage to buying premium. As long as your engine isn't knocking on regular, I don't believe you ever come out ahead on cost per MPGs. Simple as that. Most people who opt for the 6.2 aren't concerned about cost and will happily pay more for the perceived power gains.

killramos · August 2, 2019

The thing is if the engine compression specifications are designed for 93 then the engine will knock at 87, the difference between an engine in 2019 and and engine in 1976 is that the ECU can now rapidly detect the knock and electronically adjust timing to neuter the engine to prevent it from continuing to occur. That is why octane recommendations have gotten so much more loosy goosey with time. Notably the car doesn't have an octane sensor, it has a knock sensor. Detecting knock is what makes the compatibility mode kick in.

Just because it happens so quickly and seamlessly that you don't notice the switch does not mean the engine runs great on 87.

Its the same debate as putting the wrong grade of oil in your truck to save a few bucks, will it continue to run? Sure. Will it explode? Probably not. Is the engine functioning the way it is supposed to? Nope.

In terms of economic advantage, its much cheaper to buy the 5.3 and use lower octane gas and get better fuel economy to boot in near all scenarios. But that's not why you buy a truck with the 6.2.

It isn't a matter of "changing my mind", these are all just facts of engineering.

Rob41 · August 2, 2019

My last four trucks including my new T1 use 87. I've never had any issues but I do try to avoid ethanol.

aseibel · August 2, 2019

16 minutes ago, killramos said:

In terms of economic advantage, its much cheaper to buy the 5.3 and use lower octane gas and get better fuel economy to boot in near all scenarios. But that's not why you buy a truck with the 6.2.

We can agree on that.

KARNUT · August 2, 2019

In 2014 when I got my truck and joined this forum the was lots of fuel testing done with the 5.3. There was KR using 87 fuel. Mine was E-85 equip. I used E-85 locally and req gas on trips. I would switch between 87-89 to see if I saw any difference in fuel mileage cruising on the interstate. I didn’t. I do have vehicles that require premium fuel. I wouldn’t dream of using less.

Sent from my iPhone using Tapatalk

Rob41 · August 3, 2019

My 2015 had E85 capability but I chose to never use it. I also remember being told it took about a full tank of gas to calibrate fully between E85 and regular unleaded.

amxguy1970 · August 5, 2019

This is always a fun topic as there are those that say using premium they get 2 mpg better and noticeable better performance that they feel (which they can't as it is usually about 10-15 hp in vehicles that recommend premium). Either way, you can expect less than 1 mpg impact in running regular in a vehicle that recommends premium (notice that is different than required). We run regular in our 6.2 Denali, we have tried going back and forth with nothing noticeable in performance and less than 1 mpg impact. In vehicles that require 87 premium is useless, you aren't gaining anything more than a few tenths in mpg (some will say otherwise but it is just incorrect) and performance is negligible, especially to anything anyone could feel.

Came across this article comparing fuels in the same vehicles in Car and Driver, this should put an end to any discussions. Throw out the M5, 91-93 was such a small difference. Surprisingly the F150 was the largest though not anywhere near enough to make it viable in the cost aspect. Only time I would run premium is a performance car that calls for it or I am towing or hauling heavier in the heat. Otherwise, regular for me but of a the top tier variety...

BTW, the 6.2's recommend premium, not require it, runs just fine on 87 with minimal impact (maybe 15 hp and half an mpg or so). Facts are facts, but as others have noted run what makes you happy.

https://www.caranddriver.com/reviews/comparison-feature/a28565486/honda-cr-v-vs-bmw-m5-ford-f-150-dodge-charger/

Tyler

Edited August 5, 2019 by amxguy1970