To me, that sounds like the pumps are all different and your calculations might be off because of it

HOWEVER - 16MPG at 55 is very doable.

 

Dakota kid

A few folks might dispute that the same pump makes any difference... but my experience is a lot like yours...

I am a real **** and slightly Jewish old fart and I have kept meticulous records on every vehicle down to every drop of fuel. Years ago I learned computers and the wonders of AstonTate Dbase and Lotus 123. Amazing what all the different ways you can take a Long history of comprehensive data and look at.

However it gets strange when you see a trend and then on these site you get to chat with folks all around the world and they have experiences that differ greatly with your own provable experience.

In Texas, where I am, I for last 12 years tried all the local fuel depots and tended to gravitate to the easier "on the way" right side of the road gas stations. I also tended to scan the prices and hit the 2 cent a gallon cheaper place.

From 1971 to 1996 25 years living all over the USA and mostly Germany, my data shows that my method had zero impact on quality of idle, apparent power levels, and over all MPG. There are some exceptions where it was obvious that I got a load of water, crappy, or really "Bad Gas". But over all, I never detected- or my log book did not show- any distinct diff between Citgo, Shell, Sunoco, Race track or what ever. My vehicles seemed to run just fine on what ever gas I found when I needed fuel.

Around 1997-1998 this changed dramatically. My logs were showing more and more tanks of "Bad Gas". So I initially went to war with one of my local stations. (And lost BTW). Around then I also became more adept at searching and researching on the internet. Learned a whole lot about fuel, cracking hydrocarbons and such.

After I determined that the stations were not pumping any real watered down, dirty, old, "Bad Gas" I started experimenting with three tank averages from different local fuel stations. All my Nissan vehicles (mostly electronic V6s) ran better on the local Shell fuel. My Harley(s) liked RaceTrack fuel, My Kawasaki(s) did not care, my Ford diesel did not give a crap either. However the 4.6L and 5.4L Ford light truck motors ran better on Chevron. Another group that did not care was our Sentra, Escort, Jeep 6.0L, 96 SS Impala, SS 545 chev truck, the ran fine on any brand. When I got the Ford big truck, my first V10 got a whopping 1.7MPG better on Chevron and this current 2005 3v V10 gets the same with Chevron or Texaco but falls flat on ALL the off brands and actually runs terrible with more stumbles and misfires on the Clean Air blends with MTBE at 10% or 15%, but seems OK with the 5% blend.

This is really interesting because I rarely get fuel on an empty tank. Locally I top off when ever it is 1/2 tank so always adding 50% pump to the 50% already in the tank.

That is why when me and Krewat start comparing notes it is strange that he seems to get the clean air fuel at 10% and it runs just fine.

I assume Dakota Kid name means you are in the upper mid west and 89 with 10% ethanol seem to get you exceptional MPGs (though at a pedestrian pace compared to my lead foot (Grin))

 

It's better than "fine" ...

I have the CA emissions package in my '01...

I didn't notice the change over from MTBE to Ethanol here in NY. Nor from 10% eth to 100% gas. Nothing.

However, I do have to say,that the best MPG I ever got was 16.5MPG with 100% gas, but I had dislocated my shoulder, was towing my bike on a trailer, and bed full of 1000lbs of gear. I may have hit 70MPH on the way home. Nothing like my normal driving

weird....

 

Im just sayiying every body thinks these computers are so fast at adjusting and thats just not true. For example I normally get 15-16mpg driving empty and 10-12 pulling my trailer, but after I have been pulling my trailer and I refuel and rest the trip computer it takes about 100 miles of driving to get back to normal driving mileage. So therefore if you are constantly changing your fuel brand and octane you most likely will not get as good of mpg. Thats just my personal experience. (results may vary)

 

Every pump I've ever seen here as the RON (Research) + the MON (Motor) / (divided) by 2 method. I don't think I've ever seen a pump that displayed just the RON method. Anyway...
~~~~~~

So can I assume no ill effects by using gas that has a 10% ethanol mix? Hawaii just instituted all gas be a 10% mix. I know the truck can handle it but what "problems" if any, do you think I'll experience?

 

yes, it's the average between the two... which leaves a lot of leeway for the manufacturers.

On HI (notice I said "on" - it's a Long Island thing) I'd think you get "bulk" gasoline and if any of it is actually branded/mixed by any specific company, it's mixed on the islands, not before it gets there. Pretty much what we have here in NY - gas pipelines deliver bulk product. It gets to the distribution stations for each brand, and gets mixed with their additives at that point. Then it's trucked locally.

Meaning that all gas here on Long Island is made from the same base stock, but additives are put in by each company to make it what they want.

not sure when the 10% ethanol is mixed in.

If you ask me, you will notice NO difference between the two.

If you ask Fred, he'll tell you it's going to run LIKE CRAP.

Both of us are correct

 

No
I will say it depends:

It may run with zero effects OR it may run like crap and of course all points in between. My experience seems to be localized to my always at sea level truck on "straight" pump 87 and when I notice the MTBE causing me problems it is always at significantly higher altitude.

And the reason I can pin point it to the fuel is the return trips from Arizona where I have to get the blend usually have me needing to get fuel right when I cross back into New Mexico. These re-fuels are still above 4000 foot levels. After the top off with 3/4 load (about 26-28 gallons) of "straight" Chevron 87 or 89 into the 10 gallons of Chevron 10% MTBE blend I got in Tucson. It takes about 30 miles and the power comes back on and my range extends.

I have made a few of those trips out to south of Tucson a year ago when my dad was on his death bed. The effect on the empty truck running 75/85mph was not as dramatic but I could still tell she was "sluggish".

With a max GCVW of 22,890lbs it was dramatically down on power and my range was reduce by 1-3 MPGs which I consider massive no good when I am already in 7-9 mph land.

Did I mention that when this rig is hooked up to the load I am always in a hurry and like to run max safe speeds. I suppose if I backed off to a pedestrian 55-65mph trip it probably would not be as noticeable. But I defy anyone to spend 1400 miles on Intrastate 10 at those speeds. I10 is posted at 80 MPH these days and since they re worked and surfaced the entire length of her from San Antonio to El Paso, trust me it is a great highway for driving but a real attitude killer for scenery.

Side note: It was I10 and the long length of it that when we made the trip one fall in the Platinum v10 instead of my 7.3L diesel tow rig, the entire family told me on no uncertain terms... Dad we do not want to make this trip again in the PSD. The quiet of the V10 was THAT dramatic. And I, "dad, and my exceptionally patient wife, "mom" were not as rat sheet frazzled and worn out 10-14 hours later.

Monsta, not much to do about it either way for you so hope it runs fine. Sounds like this issue, on these forums, I am not in the majority. A Lot of posts where the user did not notice any difference..... and thousands of owners have trucks that never had any "straight" fuel except the factory original 13 gallons.

 

If it does run crappy after the change, maybe get the dealer to try re-flashing with other calibrations?

I seem to recall your X is still under warranty,unless you've put on 36K running around those little islands ... you poor poor *******...

 

FWIW, Hawaii has two refinerys. One owned by Chevron and the other owned by Tesoro (I think). We get ALL of our crude from Alaska and the Far East. 'Course now seems we'll get getting our ethanol from the Mid-west.

I'll wait and see what happens. If it does run crappy, I'll see about a reflash since i only have 18K miles on it. <-- Because I haven't even had it ONE year yet!

 

i have to back fred up about this bs. fuel with mtbe and grain. mine runs alfull in the winter when we get the worst of it. never gets back to normal.

and just the past 2 weeks the gas went up 30 cents and it runs even worse then before smells worse also.more like benzine from the hardware store.
i may even for the first time have to go into the dealer and say do some thing. feels like it,s missfireing lightly not enough to throw the light on ,no codes or any thing . just dame alfull running. but yet if i fill up in up/ up "around newburg" state ny or over a few countys in pa , it runs great.

with this garbage! even my carbed gas boat hates. i tryed it out this am with a full fresh load miss fired ran awfull on this stuff. and this is the old iron duke "chevy" 4 banger. man it used to run on any thing even the year old stale stuff.

i don't know maybe this abdul that owns 4 of the 7 local stations is buying some thing bad . just darn funny how they run fron brand to brand. season to season.

 

For my truck it really does not matter on the brand so much as octane. I keep very good records on all Traveling fuel. That mean that I just keep a mental note of MPG for the regular day by day driving but when I go on trips(camping, boating, traveling) I put it all down on paper. I have found the Wyoming is by far the worst and their reg is 85 while Idaho is 87. It seems that I am cheap and always try it when going through and then grip about the performance on the truck. Maybe this time around I will go for the $.10 more and get what the truck wants.

Good luck and safe driving, Robert

 

I found the same thing in Wyoming, had to bump it up a notch to stop the the ping when towing heavy.