What Fuel is everyone using?

[devildodge]

5.7/6.4 truck engine. 89 recommended 87 acceptable 0-15% ethanol. From the manual.

Seems like 93 is a waste as mentioned.(I believe somewhere it says not recommended) 89 is if you desire peak performance(really mostly for emissions/fuel mileage.) 87 will be just fine.

I have ran 87 and 89 10% ethanol and 90 non ethanol.

I haven't noticed one bit of difference towing or driving. The only difference is the final cost.

I buy gas when I am at about 26 gallon to full. If gas just went down I buy 89, if gas has been stagnant or went up I buy 87.

With 87 I got 18.4 mpg on highway trip to beach. Hand calculated at 18.1.

Do what makes you happy. Guess if you have trouble you saved money leading up to it. If you run 93 and have trouble...well you get it.

Going on our first long tow. Debating which to run. Was gonna do 90, but I was disappointed the last time I used it. Maybe so 89, but might just go 87 and enjoy the couple bucks for some snacks...got to feed this machine too.

 

[HotHareSpey]

Did y’all read the study???


“AAA found no benefit to using premium gasoline in a vehicle that only requires regular-grade fuel.”

And

“For this study, AAA did not evaluate the effects of using regular fuel in an engine that requires premium gasoline.”

******AND MOST IMPORTANTLY*****

“AAA tested 87-octane (regular) and 93-octane (premium) gasoline in vehicles equipped with a V-8, V-6 or I4 engine designed to operate on regular-grade fuel.”

Regular being 87. NOT 89. The RAM recommended fuel is 89. Toyota only requires 87. By standard of this test the RAM would not qualify for the test as it recommends 89 not regular

I tried 87 in my turbo and had terrible results - compression issues and loss of power to the point of safety

But like the above says, do what makes you happy. I have found in life that going cheap has poor results long term and kicking the can down the road hoping it will
workout never works out well

 

[SD Rebel]

I think the difference here is that Ram is recommending 89 (for best performance and MPG) but says 87 is acceptable.

Assumption is it shouldn't have any reliability or durability issues, it's just that you're not going to save any money since you will lose MPG. Might as well use 89 and get performance out of it as well.

Ford uses a different strategy with their Ecoboost, they state 87 is recommended, but if you need some extra performance such as towing, that you can use premium.

I've honestly never seen any performance differences or MPG differences between my Ecoboost or Hemi, regardless of octane use.

 

[Jtc411]

87 all day long. I’ve done several tanks of 89. Several tanks of 92. Absolutely noticed 0 impact on power or fuel economy. 20.6 is my average on screen since I took delivery of my truck. Hand calculated my tanks have always been roughly .3 lower than on screen so 20ish mixed would be pretty spot on. Always fill up at Costco or sams club. Using 87 absolutely does nothing to harm your car long term. That’s nonsense and uneducated to make that statement.

 

[HotHareSpey]

87 all day long. I’ve done several tanks of 89. Several tanks of 92. Absolutely noticed 0 impact on power or fuel economy. 20.6 is my average on screen since I took delivery of my truck. Hand calculated my tanks have always been roughly .3 lower than on screen so 20ish mixed would be pretty spot on. Always fill up at Costco or sams club. Using 87 absolutely does nothing to harm your car long term. That’s nonsense and uneducated to make that statement.

Speaking of uneducated, your reading comprehension must have had the night off

The study cited isn’t applicable to our vehicle mm’kay ?

Now try and follow along, some engines require premium fuel mm’kay?

So it matters

The recommendation from the manufacturer says to run 89 but you can run 87. Establishing there’s a difference

Has anyone run the 1500 on a Dino with two different octanes??

Until that happens there isn’t definitive evidence to suggest 87 doesn’t have long term effects or that 93 doesn’t garner max hp

However I’d be willing to bet a ribeye steak there is big time

Clarity and objectivity not bias and condescension

Your welcome

 

[SpeedyV]

87 all day long. I’ve done several tanks of 89. Several tanks of 92. Absolutely noticed 0 impact on power or fuel economy. 20.6 is my average on screen since I took delivery of my truck. Hand calculated my tanks have always been roughly .3 lower than on screen so 20ish mixed would be pretty spot on. Always fill up at Costco or sams club. Using 87 absolutely does nothing to harm your car long term. That’s nonsense and uneducated to make that statement.

As long as your knock sensors do their job and the PCM retards timing sufficiently, that’s correct. You’ll make a little less power, of course, and the engine won’t be running at optimal efficiency. But the differences are generally small.

Likewise, if the engine hasn’t been tuned to take advantage of premium fuel, it won’t do so....this would be outside of its mapped parameters.

 

[Limited_Ram]

To buy a TRUCK, and then try to penny pinch on gas is insane to me. Sounds like some would be better served buying a Prius

 

[GerryS]

As long as your knock sensors do their job and the PCM retards timing sufficiently, that’s correct. You’ll make a little less power, of course, and the engine won’t be running at optimal efficiency. But the differences are generally small.

Likewise, if the engine hasn’t been tuned to take advantage of premium fuel, it won’t do so....this would be outside of its mapped parameters.

I think this is correct. I have an old car with a high compression motor in it. It would detonated like crazy on acceleration with low octane fuel. At steady speed or idle it wouldn't knock. Probably the same deal with our trucks. 87 or 89 would be fine under idle and low load conditions. The ignition timing wouldn't get retarded by the anti knock sensors. (This could be verified with a scan tool to show idle ignition timing with both fuels.)

However, when a load is put on the engine, the anti knock sensors may kick in and retard the ignition timing with 87 and not retard it with 89.

Gerry

 

[Brisoup1]

In the owners guide, it says 89 octane is recommended but 87 octane is acceptable. It doesn't tell you why 89 is recommended.
ex: for max performance, better fuel economy etc.

 

[Brisoup1]

To buy a TRUCK, and then try to penny pinch on gas is insane to me. Sounds like some would be better served buying a Prius

Is there a truck version of the Prius? Lol

 

[Brisoup1]

To buy a TRUCK, and then try to penny pinch on gas is insane to me. Sounds like some would be better served buying a Prius

Alot of these trucks are pretty expensive. Gotta save money for the loan payment....Lol

 

[cra1g]

Speaking of uneducated, your reading comprehension must have had the night off

The study cited isn’t applicable to our vehicle mm’kay ?

Now try and follow along, some engines require premium fuel mm’kay?

So it matters

The recommendation from the manufacturer says to run 89 but you can run 87. Establishing there’s a difference

Has anyone run the 1500 on a Dino with two different octanes??

Until that happens there isn’t definitive evidence to suggest 87 doesn’t have long term effects or that 93 doesn’t garner max hp

However I’d be willing to bet a ribeye steak there is big time

Clarity and objectivity not bias and condescension

Your welcome

Thank you, Captain Irony

The study showed that using 93 when 87 is required offers no benefits. If you think that data has no relevance to using 93 when 89 is required, you just might not be equipped to make decisions like this, and should probably stick to what the manufacturer recommends.

 

[J-Cooz]

As mentioned earlier, make sure you buy 89 from a gas station with decent turnover on their 89. I'd say middle grade is the least sold octane, so you are at higher risk of old gas. If it's unusually cheap, might be the station trying to unload their tank of 89 to avoid waste. Just something to think about when debating which octane to use.

If you wind up in a pinch in a rural area on a trip, go with 87. Not worth crumming up the fuel system with questionable 89 ... wait to go back to 89 until you're back in an area with more gas turnover.

I'm pretty sure 89 is just 87 and 91 that is mixed at the pump. There's no seperate 89 tank.

 

[daberk]

I figure it's best to go with what the manufacturer recommends so I'm using 89.

 

[SpeedyV]

I'm pretty sure 89 is just 87 and 91 that is mixed at the pump. There's no seperate 89 tank.

The stations I visit around home all offer 87, 89, and 93.

A 50/50 blend of 87 and 93 would give you a 90 octane blend. To get 89, you’d need 2/3 87 + 1/3 93. Is it more likely that (1) the station pumps are capable of accurately blending that mix, or (2) this blending is done when the trucks are filled at a distribution center? I’m just curious.

 

[Gitter]

I think this is correct. I have an old car with a high compression motor in it. It would detonated like crazy on acceleration with low octane fuel. At steady speed or idle it wouldn't knock. Probably the same deal with our trucks. 87 or 89 would be fine under idle and low load conditions. The ignition timing wouldn't get retarded by the anti knock sensors. (This could be verified with a scan tool to show idle ignition timing with both fuels.)

However, when a load is put on the engine, the anti knock sensors may kick in and retard the ignition timing with 87 and not retard it with 89.

Gerry

This is exactly what I've noticed happening in my '17 Tacoma. Granted, the Atkinson V6 in the Tacoma is very picky compared to the Hemi, but the difference in gas is much more pronounced. It doesn't really give you better MPGs, it changes the ignition timing based on the amount of knock it's sensing (usualy more pronounced under load).

For instance, the Taco's are rated for 87, but their is a surprising amount of knock when using 87 while driving around town. It's because of the harder driving due to many stops followed by acceleration. Because of this, the timing gets retarted and you can really feel it after a few miles of city driving. But when driving on a long trip on the freeway, 87 doesn't feel much different than 93.

But man, when using 93, the Taco's engine comes alive when accelerating on 93 in the city. This is because there is no knock (even at WOT) and the timing isn't being retarded.

So the real question is how much do the Hemi's knock while using 87 vs 89 (or 91/93) while under load? If knock is not really an issue while driving it with 87 during your normal daily driving route, then 89 is not going to benifit you. However, if it is knocking and the timing is being changed, then it probably would be benificial to us 89 or 91+.

 

[JustAnotherGuy]

Understood, however it is backed by science. The origins of my knowledge on this are based on an article in a boating magazine. My father had numerous "Cigarette boats" growing up. Back then one of the popular workhorse motors was a Mercruiser 502. I believe it had 415 HP. Another was the Merc 500. Urban legend had tons of boaters putting premium in when the engine called for 87. It was so widely "known" that the engine ran better on premium that Powerboat magazine (I'm pretty sure it was them) did exhaustive tests on it. The result? Despite owners swearing up and down how it ran better, science proved it provided zero benefit, and in some cases the motor lost performance because it was running too rich (I think). This is very significant in the boating world when a small gas tank is 80 gallons, and many of these boats have 200-300 gallon tanks, getting less than 1MPG at speed.

There are also numerous other articles dispelling the myth, yet tons of people keep doing it:

Don’t Waste Money on Premium Gas if Your Car Is Made for Regular (Published 2016)

A new AAA report states that except in certain cases, premium offers no benefit and is a waste of money. However, brand-name fuels can still help.

www.nytimes.com

Putting Premium Gas in an Engine That Requires Regular? Stop It Now (Published 2019)

Only 18 percent of new cars require premium. The owners of the other 82 percent waste about $2 billion a year using a gas that provides no benefit.

www.nytimes.com

Drivers are wasting their money on premium gas

For years, drivers have been under the impression that premium gas was better for their car. Not so, says AAA.

www.usatoday.com

What happens when I use 91 octane gas when my car only requires 87?

Answer (1 of 26): What happens when I use 91 octane gas when my car only requires 87? You waste your money. High octane gas costs more than regular octane gas. High octane gas is exactly the same fuel as the regular fuel when purchased from the same station. The only difference between the two i...

www.quora.com

If I really dig I'll find articles from scientific bodies that have proven it provides zero benefit. Just an old myth that has a lot of street cred.

I disagree respectfully- I use 93 and it makes a difference in how my vehicles perform.

Your suggestion that 93 is a waste of money isn’t based on any science I’ve read but cleaner higher octane fuel is always better for an engine especially a large V8

 

[devildodge]

https://www.hemmings.com/blog/2014/...the-fiction-behind-those-higher-priced-fuels/

Octane does not offer any better fuel mileage,increase engine horsepower, or make the engine start quicker. Higher octane only reduces the likelihood of engine knock or ping. ... Because higher octane gas burns slower, it is more resistant to knock when subjected to higher RPM and cylinder pressures.

 

[J-Cooz]

The stations I visit around home all offer 87, 89, and 93.

A 50/50 blend of 87 and 93 would give you a 90 octane blend. To get 89, you’d need 2/3 87 + 1/3 93. Is it more likely that (1) the station pumps are capable of accurately blending that mix, or (2) this blending is done when the trucks are filled at a distribution center? I’m just curious.

It's done at the pump. If you look at most fuel trucks you'll notice they are two seperate trailers. One is regular, one is premium.

 

[devildodge]

There really is only 87 and 93 in the ground and the others are a mix. Generally speaking, today's engines can't be damaged by low octane ormixing fuels with different octanes.

Quote from an article.