Better Gas Mileage Mods

[swathdiver]

7 hours ago, KARNUT said:

My 14 GMC ran the best on E-85.

 

 

You're quite fortunate.  The problem with E-85 nowadays is that we have no idea what the alcohol content is.  It can lawfully be anywhere from 51% to 83% and still be called E-85 or Flex Fuel.  I've tried it several times and my mileage was all over the place as the alcohol content was different every time (measured by my Tech2).  The people at the stations haven't any idea what it is so it's not worth messing with unless there's a hurricane headed my way again.

[KARNUT]

 
You're quite fortunate.  The problem with E-85 nowadays is that we have no idea what the alcohol content is.  It can lawfully be anywhere from 51% to 83% and still be called E-85 or Flex Fuel.  I've tried it several times and my mileage was all over the place as the alcohol content was different every time (measured by my Tech2).  The people at the stations haven't any idea what it is so it's not worth messing with unless there's a hurricane headed my way again.

In my area there was a few choices for E-85. Prices were just under reg gas prices and much cheaper than premium gas. So the way my truck preformed on it and it was quite a bit cheaper than 93 gas was a no brainer. I would have paid more the 25 HP gain.


Sent from my iPhone using Tapatalk

[Grumpy Bear]

13 hours ago, Nickel7 said:

Settle down man! You’re taking my statement out of context and making a lot of wrong assumptions with your response. I’m a nice guy, so I apologize if I offended you. 

Apology accepted.

 

Would you care then to correct my wrong assumptions and place it in the context you intended? 

[sdeeter19555]

You make good suggestions.  This one caught me by surprise and good to know.  I thought no tailgate on an empty truck reduced resistance.

If you note, the 1500s have a wing tailgate topper and 2500s dont...the wing allows the air to roll off the top of the tailgate and miss bumper, without the little topper wing, the airflow smashes into the top of the bumper. That little deal will net 1/2mpg alone on the right truck...

No tailgate and tailgate down is very similar...with it up, a pocket or bubble of air forms in the bad, which air from the cab just glides across. Without the gate, or gate down, the air from the cab rolls off the cab and smashes into the bed floor. This hinders mileage.

Those wondering, you can watch this at diesel drags...watch the smoke from stacks. Further, I used to drive cross country and got paid mileage..the more miles per gallon I got, the more money for other things. I bought the wing deal for my last truck...1/2mpg increase. I tried tailgate up, down, off, covered, topper...the best mileage was from a topper with a small wing. I started at 17mpg and ended at 22mpg...took nearly $10k in mods to do that...

One thing I will note is that there are small mods that will net mileage; however, the money saved in mileage gains will likely not offset the cost of those mods.



Sent from my SM-T350 using Tapatalk

[sdeeter19555]

I’m a butt head so I’ll say it first. If you don’t need a truck for work drive a car. I’m retired I save 10$ a week driving a car. I have a truck not my daily driver. My car averages 30 miles per gallon, my truck average 15. It faster, easier to drive, it has a high safety rating. So if gas mileage is a problem buy a used truck for fun a car for work.


Sent from my iPhone using Tapatalk

Once I buy a new truck, I will be back into a small car for commuting.

Sent from my SM-T350 using Tapatalk

[tanner709]

9 hours ago, Grumpy Bear said:

Apology accepted.

 

Would you care then to correct my wrong assumptions and place it in the context you intended? 

You only spend a portion of your income on gas, therefore the 9.5% on your entire income statement is incorrect.

 

It's 9.5 percent, of a percentage  of your income. Say you make 60k and spend 2k a year on fuel(15-17.5k miles), 3.33% of your income. 9.5% of the 3.3% on fuel, you save 0.3% on fuel with respect to your entire income going from 19 to 21 MPG - a whopping approximate $180/year. Splurge a little and enjoy your truck whichever way suits you best.

 

I opened this thread to gain knowledge and maybe pick up a tip or trick for MPG gains but realized those small increases are hardly worth bothering with after doing the calculations.

 

Now if you can increase drastically from the low teens to 20MPG, that nets worthwhile return.

[Ravenkeeper]

On 11/15/2017 at 6:27 AM, Donstar said:

You make good suggestions.  This one caught me by surprise and good to know.  I thought no tailgate on an empty truck reduced resistance.

 

On 11/15/2017 at 7:39 AM, Grumpy Bear said:

I did to and for a long time. That is until I saw some wind tunnel test. Shortly after I read a paper from a grad student's theses he published where he and his fellows did some pressure modeling of various layouts for pickups. Then there is professional truck oval track and road racing. Tailgates and bed covers. Even when the bed is uncovered that tailgate pressurizes the box area to 'act' like a solid shape. Air is weird. It's measurement isn't new to me. I've done cylinder head work on a wet bench. It doesn't always do what seems like it should. 

 

On 11/15/2017 at 11:15 AM, aseibel said:

Mythbusters has tested the tailgate up vs. down as well as varying tire pressure's effects on fuel economy. Their results were: driving with tailgate up, and slightly over-inflated tires will give you the best fuel bang for your buck. I know their experiments are not always comprehensive, but they were interesting nonetheless.

Glad I read all the way through before responding to Donstar's post.  Was going to post a comment a lot like Aseibel did.  Grumpy, that was an interesting post.

 

When I was a Vehicle Control Officer for my last squadron, I did a lot of digging around the internet about fuel economy, prices were around $5/gal here in CA.  Most of what I had found said that the best acceleration rate is 1/4th of the throw of the throttle (4" throw, press it down 1"), use your cruise control RELIGIOUSLY, and "best MPGs happen between 45-65" (on most vehicles). 

 

Personally, I use my cruise religiously (at the speed limit), know where the long red lights are and put trans in N, limit idle times when parked/waiting, glide (N) down steep/long downhill runs (IE, SR-138, near Wrightwood, heading toward I-15), and don't drive faster than 65MPH.

 

https://www.fueleconomy.gov/

[Sierra706]

Glad I read all the way through before responding to Donstar's post.  Was going to post a comment a lot like Aseibel did.  Grumpy, that was an interesting post.
 
When I was a Vehicle Control Officer for my last squadron, I did a lot of digging around the internet about fuel economy, prices were around $5/gal here in CA.  Most of what I had found said that the best acceleration rate is 1/4th of the throw of the throttle (4" throw, press it down 1"), use your cruise control RELIGIOUSLY, and "best MPGs happen between 45-65" (on most vehicles). 
 
Personally, I use my cruise religiously (at the speed limit), know where the long red lights are and put trans in N, limit idle times when parked/waiting, glide (N) down steep/long downhill runs (IE, SR-138, near Wrightwood, heading toward I-15), and don't drive faster than 65MPH.
 
https://www.fueleconomy.gov/

Most of what you do is accurate, apart from gliding in neutral. When you do that your engine is using fuel at idle. If your coasting in gear, the forward momentum of the truck is turning the engine, as the throttle plate closes. So it’s more fuel efficient and safer for a number of reasons to leave it in drive.


Sent from my iPhone using Tapatalk

[Ravenkeeper]

On 11/17/2017 at 4:25 AM, Bushleaguechew said:

 

 

Most of what you do is accurate, apart from gliding in neutral. When you do that your engine is using fuel at idle. If your coasting in gear, the forward momentum of the truck is turning the engine, as the throttle plate closes. So it’s more fuel efficient and safer for a number of reasons to leave it in drive.


Sent from my iPhone using Tapatalk

I highly disagree.  Leaving it in Drive, on a downhill run, burns a little more fuel as you're using the engine in a engine braking form, a lot like down shifting.  In Neutral, YES, it is still using fuel, but not at the labored rate as being in Drive.  Ran these same hills in Drive and in Neutral, Neutral it shall remain.

 

NOT SAFE????  Site your source.

[KARNUT]

Going to neutral while moving is never a good idea. You could accidentally go to reverse, you could need to suddenly accelerate. I can picture someone panicking flooring the gas while they’re going back in drive not pretty. Not to mention scrubbing speed braking instead of engine braking not efficient.


Sent from my iPhone using Tapatalk

[Colossus]

I agree that you should not be shifting the vehicle into neutral while moving. 

[grizzlyltz]

Bottom line: Don't coast in neutral. It's dangerous and won't save fuel. Turning off the key at traffic lights might.


Grizzly

[WLC]

I have made numberous trips on the same route with both of my trucks. They will get the best mileage with cruise set at 59 and the temp around 70 degrees. Mileage goes up when dampness is  higher like fog or mist or light rain. Usually 24 to 26 mpg with a few stops at red lights.I always start coasting when I know a light is about to change and no rapid starts. If we could regulate the temp and humidity of the air intake of these trucks mpg's would go up even more! I'm not coasting in neutral .

[Sierra706]

I highly disagree.  Leaving it in Drive, on a downhill run, burns a little more fuel as you're using the engine in a engine braking form, a lot like down shifting.  In Neutral, YES, it is still using fuel, but not at the labored rate as being in Drive.  Ran these same hills in Drive and in Neutral, Neutral it shall remain.
 
NOT SAFE????  Site your source.

Engine braking is a closed throttle situation. It using less fuel. Your mileage display is not properly calculating the effect of coasting in neutral.

https://www.google.com/amp/www.popularmechanics.com/cars/hybrid-electric/amp5977/coasting-in-neutral-fuel-economy/


A moose runs out and you have to swerve and accelerate to avoid it. Your brakes suddenly overheat, fade and give out and there’s cars stopped at the bottom of the hill. You see a tractor trailer approaching you from behind rapidly, lights flashing and horn going clearly about to hit you and unable to stop.


Sent from my iPhone using Tapatalk

[Grumpy Bear]

You guys do know that the Ecotec3 motors, and most these days that are injected, shut the injectors off at low TPS and high vacuum...right? Can't use less fuel than zero so neutral on new motors use more fuel. Hasn't  always been true and never a safe mode of operation.