Ran 93 octane, turbos whistle really loud, and got 12.5 mpg

[Black]

Not sure what is going on. I do pretty much zero highway driving and a fair amount of sitting waiting for kiddos at school so I get a pretty consistent 15 mpg when I do highway I get about 20mpg.
Folks have claimed better mpg with 93 so figured I’d give it a go. Ran the 87 tank about as empty as possible and filled up with 93.
The turbo whistle is really pronounced and I got a whopping 12.5 mpg for the tank. No change in driving habits, no check engine light, no codes. Engine ran really well.
What gives?

 

[16plati]

Not sure what is going on. I do pretty much zero highway driving and a fair amount of sitting waiting for kiddos at school so I get a pretty consistent 15 mpg when I do highway I get about 20mpg.
Folks have claimed better mpg with 93 so figured I’d give it a go. Ran the 87 tank about as empty as possible and filled up with 93.
The turbo whistle is really pronounced and I got a whopping 12.5 mpg for the tank. No change in driving habits, no check engine light, no codes. Engine ran really well.
What gives?

What gives? “Turbo whistle is really pronounced” would be your lead foot. And if you never reset your KAM you’re truck is probably trying to figure out what to do with better fuel

 

[Black]

My foot is no different than any other tank of gas so not sure why it is much louder.
As for changing to 93 the computer should adjust itself no need for a reset simply for using a different octane level.

 

[16plati]

My foot is no different than any other tank of gas so not sure why it is much louder.
As for changing to 93 the computer should adjust itself no need for a reset simply for using a different octane level.

Ok well if you e been running 87 forever and just toss 93 in there it’s gonna take several hundred miles for it to adapt or you can just do a KAM reset like I said and have it work instantly. But what do I know, it’s not like I’ve ever done it or had same issue before...

 

[Adieu]

So basically you're revving around smalltown Kentucky on a lift and upsized LT tires when you aren't idling for A/C and radio?

12.5mpg sounds pretty impressive lol

PS also maybe no one ever buys 93 at that station, and it's rust muck and donkey piss in that tank

 

[Black]

So basically you're revving around smalltown Kentucky on a lift and upsized LT tires when you aren't idling for A/C and radio?

12.5mpg sounds pretty impressive lol

PS also maybe no one ever buys 93 at that station, and it's rust muck and donkey piss in that tank

Been getting 15 with 87 on the lift and tires and same driving habits as before.
I’ll try a reset and another tank.
Got a highway trip Thursday so we’ll see.

Never done 93 in this rig but other vehicles have and not seen a drop like this.
Maybe she’s just sensitive.

I have not been running my ODBLink recently. Wonder if the computer is allowing for more boost on the 93 and that is why I am hearing the turbos much more.

@16plati is a KAM reset the same as a PCM reset

 

[creef14]

I moved to 93 and noticed the increased turbo whistle as well

Even the owners manual says 93 will give better performance from the turbos so it makes sense that they may be making a little more noise

 

[16plati]

Been getting 15 with 87 on the lift and tires and same driving habits as before.
I’ll try a reset and another tank.
Got a highway trip Thursday so we’ll see.

Never done 93 in this rig but other vehicles have and not seen a drop like this.
Maybe she’s just sensitive.

I have not been running my ODBLink recently. Wonder if the computer is allowing for more boost on the 93 and that is why I am hearing the turbos much more.

@16plati is a KAM reset the same as a PCM reset

Yes, however, when you remove the cables from terminal, make sure you connect them with the alligator clip and turn your headlights on. It is important to drain everything from the capacitors that keep the KAM. You can also use Forscan if you are comfortable with it or a tuner. 30-45 minutes should do it the way it’s done in the video.

 

[Black]

How does one do it in ForScan?

 

[16plati]

How does one do it in ForScan?

There’s an option for it somewhere in the pcm as built data if I remember correctly. Havent done it in over a year as I have a tuner that does it for me in 15 secs now

 

[Iamsam1117]

How many miles on the truck??

I'd highly recommend cleaning your sensors and resetting the ecm at the same time. Just unplug the battery hit the high beams a few times and while it's out grab a can of contact cleaners from the local electronic store and clean the 3 primary sensors... Mine were super oiled up and dirty. I did this when I had a similar mileage drop putting in 91 octane... Running 22-23 mpg in the freeway with 91 on my current setup now

 

[Black]

62k. I actually cleaned all the sensors and my throttle body about 5k ago.

 

[Iamsam1117]

Just reset the computer or give it a few hundred miles to adjust!

 

[16plati]

Just reset the computer or give it a few hundred miles to adjust!

Try a few thousand

 

[jeff kushner]

"Things" don't change because nothing changed. If you are convinced that it is the fuel alone, then use it up, go back to your old fuel and you should be right as rain.............if not, something changed, whether it happened when you cleaned stuff or "just because" but you can take it to the bank that something is different.

I am curious though, for someone that only cruises in a pretty highly modified truck, why the 93 in the first place?


jeff

 

[TuxedoBlack]

With all the talk about low mileage issues, I started to get concerned about my mileage. I have a 15 Plat 4x4 with 3.73 LSDs and usually am reading 13.7 or so city driving. Also noted about 17 on the little highway driving I had done. Normally I use my heavy foot for throttle control. Yesterday I set the cruise at 62 and was getting 24 heading to 25mpg as the motor warmed up. I had to speed up as my wife asking me wtf i was doing driving 30mph slower than normal!

This was all on ethanoled 87.


15 Platinum Tuxedo Black

 

[Black]

"Things" don't change because nothing changed. If you are convinced that it is the fuel alone, then use it up, go back to your old fuel and you should be right as rain.............if not, something changed, whether it happened when you cleaned stuff or "just because" but you can take it to the bank that something is different.

I am curious though, for someone that only cruises in a pretty highly modified truck, why the 93 in the first place?


jeff

Seeing if I was able to notice a power gain mainly.
In some of the tuning threads people mentioned better mileage on 93 vs 87 even without a tune.
Figured I would give it a go.

 

[Boose]

I run 92 in both my F150 and Expedition. Been doing so since new. I average 22-23 on my F150 but it's all highway. I only have 3500 miles on it though, expect it to improve a bit more based on my experience with the expedition when first got it. The Expedition typically driven by the Mrs. is all around town. 15-16 is typically what she realizes hauling the kids around and such. When we go on the highway with the Expedition, I see 23-24 as long as I don't drive over 75. Cruise control does wonders with these motors on the highway.

 

[plumcolr]

If you're hearing the turbo whistle under normal driving you may have an intake duct air leak somewhere.

My 17 is consistently 20+ normal for me driving, 19+ interstate 65-75 mph.

You might check for dragging brake or something else mechanical making the engine work more.

 

[16plati]

If you're hearing the turbo whistle under normal driving you may have an intake duct air leak somewhere.

My 17 is consistently 20+ normal for me driving, 19+ interstate 65-75 mph.

You might check for dragging brake or something else mechanical making the engine work more.

He probably meant when he steps on it it’s louder. Nothing out of the ordinary there. Mine are super loud with my tune I’ve got on top of removing those “air vortex silencers” and and aftermarket CAI.