Surprising increase in truck MPG

On 2008-04-18, Steve W. > wrote:
> Ignoramus15242 wrote:
>> I have a Chevy Silverado pickup that is by now about 18 months old.
>>
>> I was never able to get more that about 220 miles out of a 22 gallon
>> tank of gas, sometimes even less.
>>
>> However, the last three refills, gave me 280, 266, and 283 miles per
>> refill. (I usually run until my tanks gets fully empty, since I have
>> an emergency gas canister for the instance when I run out of gas).
>>
>> This represents approximately 22% increase in MPG that I have hard
>> times explaining. I see three possible explanations.
>>
>> 1) Just before those refills, I did an oil change and used Mobil 1
>> synthetic oil. The previous oil changes were at a service station.
>>
>> 2) The engine had a chance to "burn in" and naturally improved its
>> efficiency
>>
>> 3) something is seriously mistaken in my measurements.
>>
>> I am at a loss and am very puzzled. Can synthetic oil really account
>> for that much of an increase? I highly doubt it.
>>
>> i
>
> Live in an area in the US that uses reformulated gas for the colder
> months? That increase is the same you would find here in NY after they
> switch over to the summer blends of gas.
>

That's possible, yes. Strange.

i

On 2008-04-18, > wrote:
> On Apr 18, 11:21 am, Ignoramus15242 <ignoramus15...@NOSPAM.
> 15242.invalid> wrote:
>> I have a Chevy Silverado pickup that is by now about 18 months old.
>>
>> I was never able to get more that about 220 miles out of a 22 gallon
>> tank of gas, sometimes even less.
>>
>> However, the last three refills, gave me 280, 266, and 283 miles per
>> refill. (I usually run until my tanks gets fully empty, since I have
>> an emergency gas canister for the instance when I run out of gas).
>>
>> This represents approximately 22% increase in MPG that I have hard
>> times explaining. I see three possible explanations.
>>
>> 1) Just before those refills, I did an oil change and used Mobil 1
>> synthetic oil. The previous oil changes were at a service station.
>>
>> 2) The engine had a chance to "burn in" and naturally improved its
>> efficiency
>>
>> 3) something is seriously mistaken in my measurements.
>>
>> I am at a loss and am very puzzled. Can synthetic oil really account
>> for that much of an increase? I highly doubt it.
>>
>> i
>
>
> Could be your part of the world just got the seasons 1st shipment of
> 'non-winter-blend' gasoline.
>
> Or maybe they were selling gasohol (10% ethanol) and stopped.

So, is "gasohol" really that much less energy dense???

i

In rec.crafts.metalworking Ignoramus15242 > wrote:
(snip)
> > Or maybe they were selling gasohol (10% ethanol) and stopped.

> So, is "gasohol" really that much less energy dense???

> i

http://everything2.com/index.pl?node=energy%20density

Gasoline is 9700 Wh/l
Ethanol is 6100 Wh/l

So, from that, 10% ethanol gasoline is: 9340 Wh/l, so somewhere in the
range of about 4% less energy dense.

Other oxygenates can have a better or worse effect than ethanol.

wrote:
>
> Get a container rated for gasoline storage.Put one accurately measured
> gallon of gasoline in the container.Mount it to the fuel intake of your
> vehicle's engine.Miles per gallon.
> cuhulin

Far easier to fill up at the same station and pump each time and to top
off the tank (despite the dire warning stickers), collect the receipt
from the pump and write the current mileage on it. Collect a handful of
these receipts and you can easily calculate a very accurate MPG.

> wrote in message
...
> Get a container rated for gasoline storage.Put one accurately measured
> gallon of gasoline in the container.Mount it to the fuel intake of your
> vehicle's engine.Miles per gallon.
> cuhulin

Man, nobody except a TV show is going to do that. Yes, feasible, but it
isnt going to
happen.

Previously posted how to measure miles per gallon.

"Ignoramus15242" > wrote in message
...
>I have a Chevy Silverado pickup that is by now about 18 months old.
>
> I was never able to get more that about 220 miles out of a 22 gallon
> tank of gas, sometimes even less.
>
> However, the last three refills, gave me 280, 266, and 283 miles per
> refill. (I usually run until my tanks gets fully empty, since I have
> an emergency gas canister for the instance when I run out of gas).


One thing that you can be sure of, synthetic oil did not result in this
perceived
increase. I have nothing against synthetics, but feel that they are
oversold
with respect to the miracles that are claimed for them.

After 18 months, you cannot hope to account for this level of increase
because of engine "wearing in". Malarkey.

You are either not measuring the mileage accurately, OR you have a different
gasoline
mixture, OR your driving conditions are grossly different from previously.

I hope I could be wrong, but it is unlikely.

Lubricants get thinner when it is warmer. Less energy loss.
Less ethanol in the fuel will give better "mileage".
Keep track of the # of miles and gallons for 10 tanks, then average them
to see if you have a "real" difference, but don't change the way or the
places you go if you want useful data.
Is anybody else driving your vehicle? My wife gets about 6 mpg
less than I do in the same car, going the same places.
Are you always getting the fuel at the same place?
No, not all fueling ramps are level, at least not where I go sometimes.
This can make a gallon difference.
The way you are measuring, you could simply have a change in the
float of your fuel gage.

Pete Stanaitis
-----------------------

On Fri, 18 Apr 2008 10:21:25 -0500, Ignoramus15242
> wrote:

>I have a Chevy Silverado pickup that is by now about 18 months old.
>
>I was never able to get more that about 220 miles out of a 22 gallon
>tank of gas, sometimes even less.
>

Where are you and what is the weather situation
My 94 TransSpert gets almost double the mileage in the summer than
what it gets in the winter - particularly around town.
Also, the engine IS now broken in on yours (mine too - I've got
100,000km on the new rebuilt)
>However, the last three refills, gave me 280, 266, and 283 miles per
>refill. (I usually run until my tanks gets fully empty, since I have
>an emergency gas canister for the instance when I run out of gas).
>
>This represents approximately 22% increase in MPG that I have hard
>times explaining. I see three possible explanations.
>
>1) Just before those refills, I did an oil change and used Mobil 1
>synthetic oil. The previous oil changes were at a service station.
>
>2) The engine had a chance to "burn in" and naturally improved its
>efficiency
>
>3) something is seriously mistaken in my measurements.
>
>I am at a loss and am very puzzled. Can synthetic oil really account
>for that much of an increase? I highly doubt it.
>
>i

** Posted from http://www.teranews.com **

Ignoramus15242 wrote:
> On 2008-04-18, > wrote:
>
>>On Apr 18, 11:21 am, Ignoramus15242 <ignoramus15...@NOSPAM.
>>15242.invalid> wrote:
>>
>>>I have a Chevy Silverado pickup that is by now about 18 months old.
>>>
>>>I was never able to get more that about 220 miles out of a 22 gallon
>>>tank of gas, sometimes even less.
>>>
>>>However, the last three refills, gave me 280, 266, and 283 miles per
>>>refill. (I usually run until my tanks gets fully empty, since I have
>>>an emergency gas canister for the instance when I run out of gas).
>>>
>>>This represents approximately 22% increase in MPG that I have hard
>>>times explaining. I see three possible explanations.
>>>
>>>1) Just before those refills, I did an oil change and used Mobil 1
>>>synthetic oil. The previous oil changes were at a service station.
>>>
>>>2) The engine had a chance to "burn in" and naturally improved its
>>>efficiency
>>>
>>>3) something is seriously mistaken in my measurements.
>>>
>>>I am at a loss and am very puzzled. Can synthetic oil really account
>>>for that much of an increase? I highly doubt it.
>>>
>>>i
>>
>>
>>Could be your part of the world just got the seasons 1st shipment of
>>'non-winter-blend' gasoline.
>>
>>Or maybe they were selling gasohol (10% ethanol) and stopped.
>
>
> So, is "gasohol" really that much less energy dense???
>
> i

Yes. If your fuel is 10% ethanol, it will have about 5% less energy
than an equivalent volume of straight gasoline.

nate

--
replace "roosters" with "cox" to reply.
http://members.cox.net/njnagel

On Fri, 18 Apr 2008 15:04:29 -0500, Ignoramus15242
> wrote:

>On 2008-04-18, > wrote:
>> On Apr 18, 11:21 am, Ignoramus15242 <ignoramus15...@NOSPAM.
>> 15242.invalid> wrote:
>>> I have a Chevy Silverado pickup that is by now about 18 months old.
>>>
>>> I was never able to get more that about 220 miles out of a 22 gallon
>>> tank of gas, sometimes even less.
>>>
>>> However, the last three refills, gave me 280, 266, and 283 miles per
>>> refill. (I usually run until my tanks gets fully empty, since I have
>>> an emergency gas canister for the instance when I run out of gas).
>>>
>>> This represents approximately 22% increase in MPG that I have hard
>>> times explaining. I see three possible explanations.
>>>
>>> 1) Just before those refills, I did an oil change and used Mobil 1
>>> synthetic oil. The previous oil changes were at a service station.
>>>
>>> 2) The engine had a chance to "burn in" and naturally improved its
>>> efficiency
>>>
>>> 3) something is seriously mistaken in my measurements.
>>>
>>> I am at a loss and am very puzzled. Can synthetic oil really account
>>> for that much of an increase? I highly doubt it.
>>>
>>> i
>>
>>
>> Could be your part of the world just got the seasons 1st shipment of
>> 'non-winter-blend' gasoline.
>>
>> Or maybe they were selling gasohol (10% ethanol) and stopped.
>
>So, is "gasohol" really that much less energy dense???
>
>i
10% ethanol costs you 5% in power because ethanol has half the
btu/gallon (roughly) of straight gasoline.
If you know one fas is E10, and the other is E0 (straight gasoline)
you are just as far ahead paying $4.20 a gallon of the E) as $4.00 per
gallon for E10.
** Posted from http://www.teranews.com **