Help...

Mikeinsmd

Mikeinsmd

New Member
I have a 2001 Dodge Sport, 4x4, Quad cab with the 5.7 V8. Purchased used last spring, I saw 14.5 mpg. Currently I am getting 11.5-13 mpg. My driving habits are as follows:
I drive to Rockville from Mechanicsville (80 mi one way) Monday mornings.
I stay in a hotel & drive 1 mile (one way) to work.
I drive home Friday afternoons (80 mi again).
I have a heavy foot (avg. 70mph on beltway, 60-65 when possible otherwise).
I run to store (4 mi one way) and to Solomons or the park (30 mi one way) occasionally on the weekends.
I use mid grade fuel (89 octane).

The truck runs great, starts soon as I turn key, plenty of power.....

WHY did my gas milage go down like it did?? Someone suggested fuel injector cleaner but if they were dirty, wouldn't I see reduced power? Plus a mechanic friend of mine says "You cant fix engines with a bottle of liquid."

Any & all ideas are appreciated!! TIA!! :cheers:
 
Railroad

Railroad

Routinely Derailed
Mikeinsmd said:
I have a 2001 Dodge Sport, 4x4, Quad cab with the 5.7 V8. Purchased used last spring, I saw 14.5 mpg. Currently I am getting 11.5-13 mpg. My driving habits are as follows:
I drive to Rockville from Mechanicsville (80 mi one way) Monday mornings.
I stay in a hotel & drive 1 mile (one way) to work.
I drive home Friday afternoons (80 mi again).
I have a heavy foot (avg. 70mph on beltway, 60-65 when possible otherwise).
I run to store (4 mi one way) and to Solomons or the park (30 mi one way) occasionally on the weekends.
I use mid grade fuel (89 octane).

The truck runs great, starts soon as I turn key, plenty of power.....

WHY did my gas milage go down like it did?? Someone suggested fuel injector cleaner but if they were dirty, wouldn't I see reduced power? Plus a mechanic friend of mine says "You cant fix engines with a bottle of liquid."

Any & all ideas are appreciated!! TIA!! :cheers:
Click to expand...
The very sophisticated computer that controls the engine will adjust everything it can to compensate for something that could rob you of power. It's not like it used to be, when the engine would run rough or something to let you know something was wrong. Try replacing the air filter and using 93 octane. Doing that, plus switching to Mobil 1 oil, took my 2002 PT Cruiser (no turbo) from 18 mpg to (most recent fillup) 29 mpg combined city/highway.
 
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Railroad

Railroad

Routinely Derailed
Railroad said:
Try replacing the air filter and using 93 octane. Doing that, plus switching to Mobil 1 oil, took my 2002 PT Cruiser (no turbo) from 18 mpg to (most recent fillup) 29 mpg combined city/highway.
Click to expand...
Fuel injector cleaner might actually help a bit, but using a good quality fuel should preclude the use of the cleaner. I've had good luck with Sheetz, BP, Sunoco, and WaWa. I've had bad luck with Exxon, Texaco, Shell, and Amoco. Also (and I never believed it until I tried it myself), periodically changing the fuel you use (e.g., changing from Sheetz to Sunoco or WaWa, and then back again in a month or so), seems to keep the engine running better. It's almost like each fuel leaves its own trash behind and the competitor's fule rinses that out. Of course, the whole theory gets shot in the butt if two different retailers are buying their gas from the same distributor. :lol: But I sure believe it works for me.
 
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Mikeinsmd

Mikeinsmd

New Member
Railroad said:
The very sophisticated computer that controls the engine will adjust everything it can to compensate for something that could rob you of power. It's not like it used to be, when the engine would run rough or something to let you know something was wrong. Try replacing the air filter and using 93 octane. Doing that, plus switching to Mobil 1 oil, took my 2002 PT Cruiser (no turbo) from 18 mpg to (most recent fillup) 29 mpg combined city/highway.
Click to expand...
Thanks RR!! I forgot to mention that I did install a new air filter & I use mobile 1 synthetic. I will try the injector cleaner (cheap fix) and using various gas stations. I mainly hit Wa Wa in Charlotte Hall Monday mornings.
 
Oz

Oz

You're all F'in Mad...
Doesn't sound like poor mileage for your rig... Suspect it will increase when the weather turns warmer.

Don't use higher octane than is recommended in your owners manual. That is a waste of money, and leads to carbon buildup in your engine. The reason they print this in your owners manual is because the engine and computer system was designed for optimal efficiency using the specified gas. The only time you use a higher octane is when the one specified is not available. (ie. My car specifies 91, but only 93 is available where I buy fuel.)

Your short trips, and the colder temps of winter are most likely what is impacting your gas mileage. Not to worry...
 
willie

willie

Well-Known Member
Oz said:
Doesn't sound like poor mileage for your rig... Suspect it will increase when the weather turns warmer.

Your short trips, and the colder temps of winter are most likely what is impacting your gas mileage. Not to worry...
Click to expand...
One mile twice a day in cold weather? Nothing (almost) could be worse. In this weather, the condensation from the throttle body to the exhaust tip has got to be horrific at the end of a one mile trip. I don't generally believe in 3000 mile oil changes but that should be the longest your truck should go before a change. I don't mean to come across as being harsh but I just couldn't do that to my car. That fuel mileage actually sounds about right for a 5.7 Mopar.
 
S

somdcrab

New Member
Mikeinsmd said:
I have a 2001 Dodge Sport, 4x4, Quad cab with the 5.7 V8. Purchased used last spring, I saw 14.5 mpg. Currently I am getting 11.5-13 mpg. My driving habits are as follows:
I drive to Rockville from Mechanicsville (80 mi one way) Monday mornings.
I stay in a hotel & drive 1 mile (one way) to work.
I drive home Friday afternoons (80 mi again).
I have a heavy foot (avg. 70mph on beltway, 60-65 when possible otherwise).
I run to store (4 mi one way) and to Solomons or the park (30 mi one way) occasionally on the weekends.
I use mid grade fuel (89 octane).

The truck runs great, starts soon as I turn key, plenty of power.....

WHY did my gas milage go down like it did?? Someone suggested fuel injector cleaner but if they were dirty, wouldn't I see reduced power? Plus a mechanic friend of mine says "You cant fix engines with a bottle of liquid."

Any & all ideas are appreciated!! TIA!! :cheers:
Click to expand...

:wah:
 
donbarzini

donbarzini

Well-Known Member
willie said:
One mile twice a day in cold weather? Nothing (almost) could be worse. In this weather, the condensation from the throttle body to the exhaust tip has got to be horrific at the end of a one mile trip. I don't generally believe in 3000 mile oil changes but that should be the longest your truck should go before a change. I don't mean to come across as being harsh but I just couldn't do that to my car. That fuel mileage actually sounds about right for a 5.7 Mopar.
Click to expand...

:yeahthat: And PLEASE don't screw with the octane
 
Mikeinsmd

Mikeinsmd

New Member
donbarzini said:
:yeahthat: And PLEASE don't screw with the octane
Click to expand...
Thanks for all the advice.... I'll check the manual to see what octane to use. I know using regular, the thing pings like crazy so I use the mid grade.
 
willie

willie

Well-Known Member
Mikeinsmd said:
Thanks for all the advice.... I'll check the manual to see what octane to use. I know using regular, the thing pings like crazy so I use the mid grade.
Click to expand...
Those very short trips can also build up carbon that will cause pre-ignition (pinging). Techron, made by Chevron, is a proven additive that will clean injectors, cylinder head carbon and even the sulphur accumulating on your fuel sending unit. Your engine computer (PCM) will compensate for the different octanes and adjust your timing accordingly but carbon in the combustion chamber throws it all out of whack.
 
John Z

John Z

if you will
[Pat Goss] Try some BG 44K fuel injector cleaner. You won't find it at Pep Boys, you'll have to go to a car repair shop (like Sullivan Goodyear in Waldorf or R&R in California). [/Pat Goss]
 
B

Bruzilla

Guest
Your 2001 Dodge should run just fine on 87 octane as that was what it was designed to use. Your computer is not capable of adjusting itself for specific octane levels, nor can it even detect the difference. In fact I don't know of any cars that can. Some engines do have ping sensors that adjust the timing, but that's not the same as detecting and adjusting for different octane levels. You should expect your car to ping during warmer months when you accelerate hard, or under moderate acceleration with the A/C on. If it's pinging at other times, you have a problem. Most likely is that one of your sensors is failing and sending incorrect data to the computer.

Using higher octane gas will decrease your gas milage. Higher octane gas is designed not to ignite as easily as low octane, and this results in unburned fuel remaining in the cylinder after the exhaust cycle, resulting in less room for fresh fuel to come in, reduced power from burning partially spent fuel, and carbon deposits.

The best way that I've found to increase milage is to change the spark plugs and replace the stock plug wires with a nice set of after markets wires (unless you have a coil on plug setup.)
 
Pete

Pete

Repete
Railroad said:
The very sophisticated computer that controls the engine will adjust everything it can to compensate for something that could rob you of power. It's not like it used to be, when the engine would run rough or something to let you know something was wrong. Try replacing the air filter and using 93 octane. Doing that, plus switching to Mobil 1 oil, took my 2002 PT Cruiser (no turbo) from 18 mpg to (most recent fillup) 29 mpg combined city/highway.
Click to expand...
I find it hard to believe your milage went up 11MPG by changing to synthetic oil and 93 octane gas. 18 to 29 is a huge leap.
 
Pete

Pete

Repete
Mikeinsmd said:
I have a 2001 Dodge Sport, 4x4, Quad cab with the 5.7 V8. Purchased used last spring, I saw 14.5 mpg. Currently I am getting 11.5-13 mpg. My driving habits are as follows:
I drive to Rockville from Mechanicsville (80 mi one way) Monday mornings.
I stay in a hotel & drive 1 mile (one way) to work.
I drive home Friday afternoons (80 mi again).
I have a heavy foot (avg. 70mph on beltway, 60-65 when possible otherwise).
I run to store (4 mi one way) and to Solomons or the park (30 mi one way) occasionally on the weekends.
I use mid grade fuel (89 octane).

The truck runs great, starts soon as I turn key, plenty of power.....

WHY did my gas milage go down like it did?? Someone suggested fuel injector cleaner but if they were dirty, wouldn't I see reduced power? Plus a mechanic friend of mine says "You cant fix engines with a bottle of liquid."

Any & all ideas are appreciated!! TIA!! :cheers:
Click to expand...
:canyousayhemi:
 
B

Bruzilla

Guest
29 MPG should be attainable on a PT Cruiser. The combined average should be about 22. Using synthetic oil will reduce friction, but it also reduces heat, which improves engine efficiency. Using 93 octane go juice will lower engine effeciency, so he probably lost a mile or two per gallon in the process.

It's hard for anyone to get a true MPG value without using lab conditions. MPG is greatly effected by traffic stops (engine running at 0 MPG), so just catching green lights can make a big difference in milage from one day to the next. Also, some gas pumps shut off earlier than others, and this can alter a fill up by as much as 1.5 to 2 gallons, which can mean a "difference" in MPG values of five MPG or more.
 
Mikeinsmd

Mikeinsmd

New Member
Filled up this morning. 12.14 mpg. I'm going to try the fuel injector cleaner & see what happens. I'm also trying not to accelerate so hard from a red light too.
 
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