Money saving tip, don't over-octane your Raptor!

[MikeD]

My computer said 11.4 avg and my calc it came to 11.1, so it's pretty accurate.

 

[Ruger]

Wait until you've done you first oil change. Nothing you do until after you get the breakin oil out of there will hold water. Secondly, your driving habits are in flux with a new vehicle. By the time you do your first oil change (at 1,000 miles, I recommend), your habits should have largely stabilized. Then to have a comparison that's worth anything you will have to keep to normalized habits, routes, traffic, etc. And in the final analysis you will find that one thing has a stronger determining effect on fuel economy in a high performance 3 ton 4x4 than all other factors combined: your right foot.

 

[svt83]

Thanks for the update and answering my questions. Again, very interesting and I will try a comparison when mine arrives.

 

[jdowens1]

See how well this works. This is a chart of what fuel is used in each state and during what month. There are many blends around 25 or so. This chart is couple years old but should still be fairly accurate.

 

[Reptar]

Do the 2012's not have two trip odomoter's? Mine has an 'A' and a 'B'. I haven't reset the 'a' since I've owned the vehicle, but I reset the 'b' every time I put gas in the truck. A gives me a good overall miles driven, gallons used, mpg, time driven and B gives me a per-tank miles driven, gallons used, mpg and time driven.

Just wondering why everyone is using calcs?!?!?!

Two trip meters, but neither one is more accurate than the other. I reset trip A every tank of gas, I plan on resetting trip B every oil change. But regardless it doesn't change the fact that those meters for fuel ecomony are just the computers estimations. Hand calcs tell you exactly what fuel economy you got.

Reptar, when doing your hand calcs, have you noticed that the numbers are much different from the ones that your productivity screen tells you? If so, is it consistently "inaccurate?"

My hand calc #'s have always been less than my display #'s.

1st tank of 93 showed 13.7-13.8 on the display and it was 13.2 actual. 2nd tank of 93 showed 13.9-14.0 on the display and it was 13.5 actual. This tank is showing 14.8-14.9 on the display so I'm expecting it to be around 14.4-14.5 actual? Which is still roughly a 1 mpg jump. And I'm not attributing that all to break in. For the same driving pattern, the truck isn't going to improve by 0.3 mpg from tank 2 to 3, then by 1.0 mpg tank 3 to 4, just from breaking in. Vice versa would be true if anything, but that's not the case. Truck has already seen the major jumps from breaking it in, at this point the improvement from breaking it in is minimal. It may be another 0.2-0.3 improvement from breaking in, but there's definitely a factor in there that the truck prefers 91 over 93.

The crummy part is 91 is only TWO CENTS a gallon cheaper here than 93. There's no real savings till you drop to 89 or 87. It would cost me another $0.68 to fill my entire tank with 93 over what it would to fill it with 91. That's a total wash, which is why I wouldn't mind putting 93 in it. But from what I'm seeing, the truck actually likes 91 better. So I'll save that 68 cents I guess and save it up, after a couple months I'll be able to buy a #2 on the Value Menu at McDonalds

Wait until you've done you first oil change. Nothing you do until after you get the breakin oil out of there will hold water. Secondly, your driving habits are in flux with a new vehicle. By the time you do your first oil change (at 1,000 miles, I recommend), your habits should have largely stabilized. Then to have a comparison that's worth anything you will have to keep to normalized habits, routes, traffic, etc. And in the final analysis you will find that one thing has a stronger determining effect on fuel economy in a high performance 3 ton 4x4 than all other factors combined: your right foot.

I'm well beyond 1k miles, already at nearly 1,500. My driving habbits haven't changed the past few tanks. The first tank was 450 miles, plenty of time for me to get accustomed to the truck, romp around a bit, vary the RPMs and break it in well, so at this point, it's just casual daily driving. Same daily routine, week in, week out. Same exact treck, tank in, tank out. Been very light with the right foot on every tank but the 1st one. If I want to romp around and go fast, I hop in my 700+ rwhp 10 second harley truck, or go bang gears in our 5.0, rather than waste my time trudging along in a 6k lb truck pretending its fast lol

See how well this works. This is a chart of what fuel is used in each state and during what month. There are many blends around 25 or so. This chart is couple years old but should still be fairly accurate.

View attachment 6845

Too small to read, but defintiely a consideration, as I mentioned I always see a drop on winter blend fuels.

Fortunately so far in this comparison, even the temperature has been basically the same the past month I've had the truck. Typically 50's most of the week, occasional dip into the 30's, other than that, a really boring winter, week after week after week.

 

[jdowens1]

I was afraid it might be to small. Maybe someone might be able to make it biggger so it is readable.

 

[Humvee21]

I think the way the computer estimates mpg's is by measuring the amount of airflow with the MAF? More air = more gas used. If this is wrong, please correct me. If not, this could explain why the estimations are not that accurate.

I was afraid it might be to small. Maybe someone might be able to make it biggger so it is readable.

Impossible. I see that you used forum runner to upload the picture. How about you send the file to one of us and we can upload it for you.

 

[Reptar]

I don't think it bases it off the MAF directly. My assumption would be that since the computer drives the injectors to whatever predetermined duty cycle, it should be able to compute how much fuel has flowed through the injectors, coupled with how many miles have been driven, to calculate that fuel economy.

I'd be interested to see what interval it averages the mpg over though. I thought I read somewhere it was averaged over the past 500 miles unless you reset it. That may have just been for the miles to empty calculation though.

 

[Hocker52]

Every time I fill up I put in about 1.3ga or so more in than what the computer shows I used. So it shows I'm getting better milage than I actually am.

 

[FireLT]

My truck has always has always had 87. Ave mpg is at 15. 18k miles.