Huge Mpg Drop, For My Charger....

[Blue88Comanche]

So I filled up my charger today, normally i get 18-19 mpg but today when i filled up i got 16 MPG...  I did not change how i was driving, did not sit with the engine running.  the car drove like it always does, no issues on performance.  I know its time for an oil change, maybe something oil related caused MDS not to kick in...  idk..  next tank will show if this trend continues.

 

Check engine light is not on, but will double check this afternoon and run my scanner on it.

[Oyaji]

Do any extra driving in town? Take a roadtrip with a significant headwind? Carry a load of anvils to auction?

 

Most likely: you filled up at a different location than usual. If your car was not sitting level when you filled it, you could have gotten a big air bubble at one end of the tank that prevented a complete fill on your previous tank, then this fill-up had to make up for it with extra gas.

 

Kudos to you for keeping track of your fuel usage and economy! It's a great indicator of how well your engine is running. I always keep track, and log any unusual running conditions that might affect economy so that when I am in your current position I am not left scratching my head. I suggest doing what I do: watching the average economy over the last 3 tanks, and if a trend is evident, seeking out and remedying the cause.

 

PS - would you help me keep an eye out for a cheap Comanche or 2 in the area, especially 91s/92s? I'm just east of you 1 county...

[carnuck]

Do they switch to "winter" fuel out there? They did here recently and I dropped from 17 to 14 mpg the last 3 tanks.

[onlyinajeep726]

"Winter" fuel? :hmm:

[Oyaji]

"Winter" fuel? :hmm:

Yeah, Carnuck is right to mention it. In 4-season climates, gasoline is reformulated for the different temperatures encountered through the year. In winter, a greater amount of higher distillates are added to reduce vapor pressure, which makes for easier cold starts. In summer, this is changed to reduce fuel boiling in hot fuel lines near the engine to reduce vapor lock starting problems.

 

I don't know to what degree (if any) gasoline is changed around here for the changing seasons. We are still pretty warm here - still haven't had our first freeze, and our winters are very mild (no snow and very infrequent hard freezes - none for the past 3 years). I know in recent years gasoline formulation has gone to crap in general, so it would not surprise me to find that seasonal changes in gasoline composition result in significant changes to fuel economy.

[gogmorgo]

I don't know if I really buy into the winter fuel thing. Diesel, yeah, it prevents gelling, but with gas I think it just has line anti-freeze in it, or some kind of water remover.

[carnuck]

alcohol of 10% minimum here in WA.

 

http://pure-gas.org/

 

Try filling at one of the stations on this list. Don't forget that outside temps affect fuel as well. Cold fuel doesn't atomize as easily.

[Incommando]

"Winter fuel/ Summer fuel" is a reality in the U.S.  I am not sure about Canuckia.  It is actually an emissions  thing. You can search it up on many websites:

http://auto.howstuffworks.com/fuel-efficiency/fuel-consumption/summer-fuel1.htm

 

 

Is it effective? Not sure. It is like the E85 lie: 25% of the cost at the pump...with 25% less efficiency to make it even out and then less potential power to make it a sucker's bet.

[Blue88Comanche]

Do any extra driving in town? Take a roadtrip with a significant headwind? Carry a load of anvils to auction?

 

Most likely: you filled up at a different location than usual. If your car was not sitting level when you filled it, you could have gotten a big air bubble at one end of the tank that prevented a complete fill on your previous tank, then this fill-up had to make up for it with extra gas.

 

Kudos to you for keeping track of your fuel usage and economy! It's a great indicator of how well your engine is running. I always keep track, and log any unusual running conditions that might affect economy so that when I am in your current position I am not left scratching my head. I suggest doing what I do: watching the average economy over the last 3 tanks, and if a trend is evident, seeking out and remedying the cause.

 

PS - would you help me keep an eye out for a cheap Comanche or 2 in the area, especially 91s/92s? I'm just east of you 1 county...

 

all my driving is the same everyday to to and from work.. maybe twice a month i will drive into town after work..

 

I drive about 40 miles a day to and from work and between our two locations. (14 miles one way to work highway most is 55 MPH speed limit)

 

usually i fill up at one of two gas stations, only once have i used another. and i try to use the same pump every time.

 

I did check my oil and it is at the add line..  I think i read somewhere that the MDS only works with certain oil weight, and oil level.. I would add oil but i am unsure if it has full synthetic or a blend, 

 

there are no engine codes.

 

 

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I will keep an eye out for you if i come across one.

[Blue88Comanche]

they say the MDS should increase fuel economy up to 20%

 

16 + 20% = 19.2

 

if my math is right that is

16 x 1.2 = 19.2

 

Just a thought

[Oyaji]

Watch your economy over the next 2 tanks and look for confirmation of a trend, then... and find out what kind of oil you have in that thing and top it off!  :D

[Blue88Comanche]

it needs an oil change anyway, I may take it to the dealership Saturday. and let them change the oil, top off fluids, check the transmission fluid, and re-calibrate the speedometer to accommodate for the shorter tires the last owner put on it...

 

if the trend continues, somethings up

[gogmorgo]

"Winter fuel/ Summer fuel" is a reality in the U.S.  I am not sure about Canuckia.  It is actually an emissions  thing. You can search it up on many websites:

http://auto.howstuffworks.com/fuel-efficiency/fuel-consumption/summer-fuel1.htm

 

 

Is it effective? Not sure. It is like the E85 lie: 25% of the cost at the pump...with 25% less efficiency to make it even out and then less potential power to make it a sucker's bet.

http://www.petro-canada.ca/en/wholesalefuel/318.aspx

Not so much an "emissions" thing up here. Mostly it's billed as having de-icers, although the difference in evap rates is mentioned, although more in the sense that winter fuel atomizes more readily in cold air.

Is it a lie? Don't know. The science behind it holds up, at least.

The reason I don't much care for it is that de-icers aren't always so great on the plastic and rubber bits in your fuel system.

 

The biggest lie with ethanol is that it takes more energy to produce it than we can get out of it when you make it out of corn the way we do in North America. In markets where it's mostly sugar-cane based, then it actually works out a bit better.

[Blue88Comanche]

Well I decided to change the oil my self so I would know exactly what oil was in it... And due to the shorter tires used by the last owner, I just bearly can't use my ramps... If it had the proper tires I would be fine. Guess I will be taking it to the quick lube shop after all...

[Incommando]

I have also found the MPG of my injected vehicles to be very sensitive to a dirty air filter.

[Oyaji]

I have also found the MPG of my injected vehicles to be very sensitive to a dirty air filter.

 

If you say so. But wouldn't it have to be really dirty to obstruct flow more than the throttle butterfly valve? It is mostly closed for almost all running conditions, even during most accelerations, at least for me... but then I am a slow, stingy, methodical driver who is trying to eke out the best fuel economy possible.

 

By the way, I am making an effort to memorize and use the line in your sig about vegetarianism - it's great! "I am a vegetarian by proxy. I only eat animals that eat vegetables."  :rotf:  :rotf:  :rotf:

[Incommando]

I admit to driving, um, aggressively. I generally replace the filter more often than recommended and notice my various turbo cars from over the years seem to be more sensitve. I can often bang the old filter onto the ground and it leaves behind a pattern reminiscent of a a vacuum cleaner fliter. Maybe it is my geographic area? I wish the sig line was original but I have no idea where I heard it form originally.

[carnuck]

Mine have been more sensitive to dirty injectors (the Amsoil PI does a good job)

[carnuck]

"Winter fuel/ Summer fuel" is a reality in the U.S.  I am not sure about Canuckia.  It is actually an emissions  thing. You can search it up on many websites:

http://auto.howstuffworks.com/fuel-efficiency/fuel-consumption/summer-fuel1.htm

 

 

Is it effective? Not sure. It is like the E85 lie: 25% of the cost at the pump...with 25% less efficiency to make it even out and then less potential power to make it a sucker's bet.

 

They tried 15% in BC (Mohawk stations had 7.5% methyl and 7.5% ethyl blended to 85% gas) and cars were catching fire all over the place and breaking down because factory cars weren't being made to handle alcohol and fuel lines split, injectors self destructed (my wife's '84 Nissan 810 wagon almost caught fire on the SR520 bridge!)

[Blue88Comanche]

I took it up to my local quick lube that one if our friends own. They swapped out the oil and filter (with my oil and filter), checked the air filter, would have topped of the washer fluid have I not told them I use my own stuff, checked the tire pressure, and discovered my car was one of the few Chrysler brand cars that actually had the cabin air filter. It was also changed out because it WAS very dirty. In and out in maybe 20 min. Faster if I was not chatting with them..

 

I went with mobile 1 full synthetic, the higher tier of it what ever it was... I haven't realized that the 5.7 uses 7 quarts of oil!

 

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I usually drive conservatively, however if I am getting on the interstate (I rarely do) then I drop it into auto-stick and floor it! I could easily hit above 80 before I even leave the exit ramp.