People with gas mileage issues

[PowerJrod]

Another wrench to throw in here (sorry if it was discussed earlier and I missed it), sometimes the gas companies cheat until they get caught cheating.

A year or two ago, we had an incident in my area (south eastern South Dakota) where one of the major gas distributors was caught putting 85 octane into 87 octane tanks, and had been doing it for a little while.
The western part of South Dakota is right at the cut-off elevation where, theoretically, you can start using 85 octane instead of 87, so it was easily available to the distributor.
They claimed it was to avoid shortages (yeah huh, sure it was), but couldn't provide reasoning as to why they didn't tell anyone outside their company. They were fined, if I remember correctly, and had to stop doing it.

So you may sometimes think you're using 87, when you're actually using 85. Whereas if they happen to cheat on 89/91/93 and go down to the next octane level, you're still getting 87 or higher.

Also, ethanol hurts. I've said it before, I'll mention it again; my 2014 with the 5.7 seemed to like 87 octane with no ethanol better than 89 or 91 with 10% ethanol. Usually saw a couple MPG bump in highway driving. I deal with it, Costco in my area only sells 10% ethanol fuel, and get 91.

That's a good point...it's like the equivalent to when you pay for a full synthetic oil change and you get something different.
But this is one of the reasons why they mention TOP TIER....The top tier stations are the ones that are tested more often than the others.

 

[PowerJrod]

Major corporations do not put out recommendations for safe operation that requires you to read between the lines. Anything shy of explicitly stating you cannot use it continuously opens FCA up to legal repercussions in the event of failure. Not sure how else to convince you otherwise. Best of luck!

Right...because no company ever has fine print. Lol...Naive nonsense. You can think what you want but I know better based off experience. Like I said....this was already confirmed by a RAM service tech...so you're barking up the wrong tree trying to convince me of that nonsense.

 

[Wsmith]

I'm using 87, truck is still new. Every time I go to the pump I wan't to put 89 in it, but I don't. In the "olden days" mid grade was $.10 higher than regular, premium was $.10 higher tan mid grade. Things have changed its now like $.50 higher than regular and premium is $.90 to $1.20 higher than regular. I know I should go 89, but each time I stand at the pump, which is a lot. I always cheap out.

 

[PowerJrod]

Major corporations do not put out recommendations for safe operation that requires you to read between the lines. Anything shy of explicitly stating you cannot use it continuously opens FCA up to legal repercussions in the event of failure. Not sure how else to convince you otherwise. Best of luck!

Oh, and another thing....them stating that 89 octane is recommended already closes the possibility of a lawsuit and warranty claim by law.

 

[PowerJrod]

I'm using 87, truck is still new. Every time I go to the pump I wan't to put 89 in it, but I don't. In the "olden days" mid grade was $.10 higher than regular, premium was $.10 higher tan mid grade. Things have changed its now like $.50 higher than regular and premium is $.90 to $1.20 higher than regular. I know I should go 89, but each time I stand at the pump, which is a lot. I always cheap out.

I completely understand...but then again...you shouldn't have gotten a $50k truck if you can't afford the gas...or you should've gotten the V6. Irresponsible.

 

[Willwork4truck]

85 or 87 seems to be regional. When I visited my brother in the Denver area this summer there was a lot of 85. Fortunately in my area the lowest is 87.

Now the argument about running E-10 vs E-15 vs pure gas is more interesting to me. My local Sheetz store offers 87 E-10, 88 E-15 and some 100% gas. Usually the 88 E-15 is at least .10 cheaper than the E-10 and the pure gas is roughly .50 more than The E-10 87 octane.

 

[Shives]

89-91 only. I won't do the lesser anymore.

 

[PowerJrod]

89-91 only. I won't do the lesser anymore.

Finally... someone that gets it lol!

 

[Wsmith]

I completely understand...but then again...you shouldn't have gotten a $50k truck if you can't afford the gas...or you should've gotten the V6. Irresponsible.

I like you too.

 

[Wsmith]

Oh, and another thing....them stating that 89 octane is recommended already closes the possibility of a lawsuit and warranty claim by law.

No it doesn't. It states that 87 is acceptable.

 

[Dusty1948]

Another wrench to throw in here (sorry if it was discussed earlier and I missed it), sometimes the gas companies cheat until they get caught cheating.

A year or two ago, we had an incident in my area (south eastern South Dakota) where one of the major gas distributors was caught putting 85 octane into 87 octane tanks, and had been doing it for a little while.
The western part of South Dakota is right at the cut-off elevation where, theoretically, you can start using 85 octane instead of 87, so it was easily available to the distributor.
They claimed it was to avoid shortages (yeah huh, sure it was), but couldn't provide reasoning as to why they didn't tell anyone outside their company. They were fined, if I remember correctly, and had to stop doing it.

So you may sometimes think you're using 87, when you're actually using 85. Whereas if they happen to cheat on 89/91/93 and go down to the next octane level, you're still getting 87 or higher.

Also, ethanol hurts. I've said it before, I'll mention it again; my 2014 with the 5.7 seemed to like 87 octane with no ethanol better than 89 or 91 with 10% ethanol. Usually saw a couple MPG bump in highway driving. I deal with it, Costco in my area only sells 10% ethanol fuel, and get 91.

We had a similar incident here about 5-6 years ago. Eighty-five octane isn't marketed here, but one company was pumping 85 for 89.

Ethanol fuels are a bit more unstable as they have a tendency to absorb moisture.
Regards,
Dusty
2019 Ram 1500 Billet Silver Laramie Quad Cab 2WD, 5.7 Hemi, 8HP75, 3.21 axle, 33 gallon fuel tank, factory dual exhaust, 18” wheels. Build date: 03 June 2018. Now at: 037958 miles.

 

[UnloosedChewtoy]

Ethanol fuels are a bit more unstable as they have a tendency to absorb moisture.

Yep! Thats exactly why you don't want to use ethanol in fuel placed into storage or in a vehicle that will not be run for months. Not without an additive to counteract the ethanol anyway.

 

[PowerJrod]

No it doesn't. It states that 87 is acceptable.

The manual doesnt state that 89 is recommended for the 5.7??? You might want to recheck that lol. 87 Acceptable for how long? (That's a rhetorical question) but I think you get my point. No sense in arguing.

 

[Wsmith]

The manual doesnt state that 89 is recommended for the 5.7??? You might want to recheck that lol. 87 Acceptable for how long? (That's a rhetorical question) but I think you get my point. No sense in arguing.

I agree that I am not going to argue. Look at the fluid and lubrication specs for the 5.7 "89 octane recommended - 87 octane acceptable" I don't think using an acceptable octane fuel is "irresponsible". After all I'm not putting 87 octane in your ram.

 

[JF19Longhorn]

On perfectly level ground with no wind I 'might' see 18-20mpg on the instant readout. Which on my truck, is a 17-19mpg actual. ..but the moment there is an overpass, slight incline to the road, a leaf blowing in the wind, the sun shines in the wrong direction.. it's down to the low teens. My MDS never kicks in above the 40's unless there is a very long down hill stretch.

I drive mostly hwy and, last I checked on Fuelly, the lifetime avg is 15.9mpg. 89Oct, 3.92's, Hemi w/ Etrq, 9k miles on the clock.

 

[PowerJrod]

I agree that I am not going to argue. Look at the fluid and lubrication specs for the 5.7 "89 octane recommended - 87 octane acceptable" I don't think using an acceptable octane fuel is "irresponsible". After all I'm not putting 87 octane in your ram.

My Ram heard you say 87 octane and it cringed lmao!

 

[Tydog96]

Recently picked up a special order Limited 4x2 with 3.21 eTorque, 20" tires, rambox, and immediately put about 4000 miles on it (Okla to Utah to Georgia), but babied it around the first 500 and took the 'time' hit to do that (varying speed, stopping, just no much cool downs). No opportunity to cool down engine much on first two days OK to Utah. I have been getting around 20.x and 21.x mpg on highway at around 65, down as I get 70mph and above. Since back home, I 'm seeing around 17 around town to work and back (8-10 stop lights in about 8 miles). I'm not unhappy with it. Trip was with two people, a new BAK Mx4, and a bed of travel stuff (a couple of ice chests, tools, oil for a 1500 miles oil change ,etc.). This was dash MPG. Now doing a in-town pump review. Whatever it is, it's significant better then my 5.2L Gen2 in MPG and in all other the ways. Love the lane assist and other safety features. Just getting used to the bulking size from the '98 Gen2. Perfect truck, no. But an excellent truck for long distance comfort and safety for sure. Ran medium grade to high grade. Love the 33 gal tank as i can fill up with gas selection and not have to search out as often. Just wish I could brighten up the RDL (no low beam mode). Rear sway bar and mudflaps waiting in garage for this weekend. Forum is much appreciated during the wait on the truck (ordered first of June, arrived last of July. Picked up 8/6.

 

[Jako]

My Ram heard you say 87 octane and it cringed lmao!

Pretty much always run with 89. But was filling up (25 mile range to empty) at local station and felt their 89 could be "stale" so filled up with 87 for a 150 mile trip which at the conclusion I would fill with 93 to bring back up to 89. The trip was on the NJ Tpk and other highways. Maintained speed limit throughout and at one point hit 25 mpg on trip meter. My 5.7 hemi seemed happy.

 

[BowDown]

I'm getting 18 mpg both on the display and calculating it on refills, almost all city driving, 85/15 city vs highway.



As for octane and knock, that has more to do with engine load, IAT (intake air temp) and fuel octane.
High IAT's are truly what causes knock, you can run 87 with no damage occurring as the PCM simply pulls timing until the knock ceases, you can watch this occur on HP Tuners or a cheap scanner on almost any car.
In theory, 87 should be the best fuel as it burns quicker (octane rating is a measure of a fuel's ability to resist knock), a quicker fast explosion in the combustion chamber makes more power AS LONG AS THE PISTON is at the correct position usually just before TDC. If the cylinder fires too soon before TDC (detonation/knock/pre-ignition) the piston is still traveling up when the fuel air mixture is firing. This causes piston rattle which is the knock you hear. This knock is the piston rocking on the pin in the cylinder (because of short piston skirts to save money) and leads hammering the rod bearing and eventually causes the rod bearing to egg shape creating excessive clearance. and permanent damage.
Higher Octane fuel has a resistance to knock by burning slower giving the piston time to get closer to the ideal firing position and creating more leverage on the rod/crank creating more torque which translate into more power (HP is a measure of torque which is why I only focus on TQ). This is the same reason lawnmowers specifically state NOT to run fuel higher than 87 in them, they have no mans of compensating for higher octane fuel and a slow burning fuel will cause them to not make advertised power and run too hot.

I run 93 in the summer due to the fact that IATs are typically in the 115-120 degree range in the summer, this air temp combined with engine load can cause knock. High IAT's = thinner lower DA air and more knock potential. In the winter, I drop back down to 89 once the IAT are consistently under 95-100 degrees.
My car is a different story, its 9.6:1 dynamic compression, static compression is meaningless, and that requires a 93 map in the winter but the E85 map in the summer just to be safe.

Also, eTorque makes no difference, engines start on a low timing start map to make cranking easier, timing doesn't come in until 5-600 rpm. Try cranking an engine with all the timing in, that's what burns out starts, load is too high

 

[Timeless]

Try again. It's in the manual. Not the part where there's the giant number 89 or 87. Keep reading a few pages down. It says 87 is "acceptable". That doesn't mean you should use it continuously.
The other thing that might have contributed though...was him not using TOP TIER gas...even the manual states to use TOP TIER. You two can interpret how ever you want...but I know how to read between the lines. Like I said...service tech already confirmed it to be low quality gas with not enough octane....good luck trying to argue with a RAM service tech lol.

Ram and others allow the 87 because the octane sensors work properly and adjust timing based on what you use. Thus it is acceptable and will not void any warranty claims.

What does suffer is peak horsepower/tq as the maximum is based on the higher recommended octane of 89.

Thus 87 will see a slight drop and anything above 89 will not see anything better as the computer is not programmed to advance the timing past 89 octane readings.

For the vase majority of drivers they would never know the difference.

For me the Sams Club/Costco premium is the same price as 89 at regular stations or cheaper, so I typically mix the 87 and 93 between fill ups to average 89 or more....just because that is my personal preference.

Where you can typically see a large change is turbo motor vehicles. Usually around a 20-30 HP delta between 87-91 which should be noticeable.