Better Gas Mileage with 87? Hmmm

[ant0064]

I have about 3500 miles on my 2019 Laramie now. I've been using 89 up to this point but recently filled up with 87 for the first time. I'm getting about 1 - 1.5 MPG better than 89 with the same driving habits and noticed it immediately. Anyone else experience this or have any explanation??

 

[snj1013]

Is the 87 octane fuel you used Ethanol Free? That might be one explanation, but other than that, I would guess you have an outlier in your sample and the increase in MPG won't reoccur.

 

[ant0064]

Is the 87 octane fuel you used Ethanol Free? That might be one explanation, but other than that, I would guess you have an outlier in your sample and the increase in MPG won't reoccur.

I usually purchase gas at BP...the only change is from 89 to 87. I'll have to see if it continues and do a little experiment.

 

[riccnick]

My guess is it's placebo. Are you going off the EVIC readout or hand calculating?

 

[J-Cooz]

Could be the truck breaking in too. My mileage was pretty bad for the first few thousand miles and now it's getting better and better. Averaging around 18-19 with mostly highway.
Hemeeeetorque with 3.92

 

[Rob5589]

Entirely possible but, not likely. Here is an interesting take on reg vs. premium.

Premium vs. Regular

Is premium gas worth the premium price? Tom and Ray set the record straight on gasoline.

www.cartalk.com

 

[Snakes709]

I recently did a 6000km trip. Tried 89 for the first part, accidentally filled with 91/93 in a few states and 87 for the last half of the trip. Not a single difference in mileage. Its a placebo effect.

 

[Dusty1948]

I have about 3500 miles on my 2019 Laramie now. I've been using 89 up to this point but recently filled up with 87 for the first time. I'm getting about 1 - 1.5 MPG better than 89 with the same driving habits and noticed it immediately. Anyone else experience this or have any explanation??

I had two 4th gen 1500s (DS), one with the six speed, and the later one with the 8-speed. I tirelessly keep track of gas mileage and tried running 89 at various times. Frankly, I could not empirically say I realized a difference, either in gas mileage or "feel." Both of those had a 3.92 axle ratio, so it's possible that masked any real detectable difference.

My '19 has the 3.21 axle, but I haven't tried 89 octane yet.

Best regards,
Dusty
2019 Ram 1500 Silver Billet Laramie, Quad Cab, 2WD, 5.7 Hemi, 8HP75, 3.21 axle, 33 gallon fuel tank, 18 inch wheels. Build date: 17 April 2018. Now at 020428 miles.

 

[Billet1500 4x4]

I recently did a 6000km trip. Tried 89 for the first part, accidentally filled with 91/93 in a few states and 87 for the last half of the trip. Not a single difference in mileage. Its a placebo effect.

I did a similar test. 3 tanks of 87 followed by 3 tanks of 89 followed by 3 tanks of 91. Same gas station just different grade. Actually got worse fuel economy on 91 versus 87 and 89 which were the same fuel economy wise.

 

[Str8Cracker]

Same here and don’t understand. 14,000 miles on my truck and I began to notice the computer always got about 1mpg better on 87 then 89. Just recently did a long multi state trip and decided to hand calculate the mpg and it confirmed what the computers been telling me. I only use Shell gas and why it’s possible my long road trip could have had some variables, I can’t seem to prove what my common sense is telling me isn’t possible. I don’t get it.

 

[cheyfinn]

I went to Denver Saturday 8/24/19 I have 1000 miles on the truck and got 22 mpg on it , 3.21 gear 87 octane running at 80 mph on the interstate, very happy with the mpg , my '10 hemi got 18 mpg on the hi-way