Gas mileage help
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Joined: Apr 2003
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From: Tucson
Gas mileage help
I have a 2000 Exp. XLT with 5.4L engine. I have a GIBSON exhaust, K&N filter not FIPK kit, 315-75R-16 BFG all-terrains, 3.73 limited-slip differential, superlift suspension (4"). I have read several of the posts here, and some point to a Chip module, but I am looking for specific things people have done to this engine to get better gas mileage. I currently average 11 MPG whether I am highway driving or in the city. Any suggestions would be great, but specifics would be better. Thanks.
-Todd
-Todd
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Joined: Oct 2002
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From: MA
Gas mileage help
11 huh? Sounds too low to me. I had a 01 F150 with the 5.4, KN filter, throttle body spacer, and gibson catback, and I got 15 in town, 17 on highway with 275/60? tires. What does your 315's equal in inches? Did you recalibrate your speedo for the taller tires? Have you gotten a tuneup lately?
Rich
Rich
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From: Tucson
Gas mileage help
Rich,
I checked online and it is 34.6 inches. It hasn't had a tuneup in a while. Is it worth taking it to a shop, or can I just replace the spark plugs and save myself some money? The speedo hasn't been fixed for the bigger tires, however I have used several methods and found that it is off by 11 MPH. I use this and checking it against mile markers to calculate the actual mileage the truck has travelled, so that the MPG are accurate. Thanks.
-Todd
I checked online and it is 34.6 inches. It hasn't had a tuneup in a while. Is it worth taking it to a shop, or can I just replace the spark plugs and save myself some money? The speedo hasn't been fixed for the bigger tires, however I have used several methods and found that it is off by 11 MPH. I use this and checking it against mile markers to calculate the actual mileage the truck has travelled, so that the MPG are accurate. Thanks.
-Todd
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Joined: Apr 2003
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From: Fort Wayne, IN
Gas mileage help
I'm running a 5.4 with no cool stuff yet.
Just made a trip to Bristol, VA (read Smoky Mountains), I got 17.1 round trip. Typical Interstate I'm running about 18, 14 kicking around town. Looking at a few things to improve overall performance and possibly mileage.
Just made a trip to Bristol, VA (read Smoky Mountains), I got 17.1 round trip. Typical Interstate I'm running about 18, 14 kicking around town. Looking at a few things to improve overall performance and possibly mileage.
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Joined: Apr 2003
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Gas mileage help
Originally posted by TCExp
I'm running a 5.4 with no cool stuff yet.
Just made a trip to Bristol, VA (read Smoky Mountains), I got 17.1 round trip. Typical Interstate I'm running about 18, 14 kicking around town. Looking at a few things to improve overall performance and possibly mileage.
I'm running a 5.4 with no cool stuff yet.
Just made a trip to Bristol, VA (read Smoky Mountains), I got 17.1 round trip. Typical Interstate I'm running about 18, 14 kicking around town. Looking at a few things to improve overall performance and possibly mileage.
I just bought an K&N lookalike, and installed ($58). I avg 12 mpg so I know the pain. I was told this will add 2-3 mpg and axhaust cat-back will add the same. Anyone else have other suggestions?
Senior User
Joined: Apr 2003
Posts: 196
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From: Fort Wayne, IN
Gas mileage help
Originally posted by jeffymac
I just bought an K&N lookalike, and installed ($58). I avg 12 mpg so I know the pain. I was told this will add 2-3 mpg and axhaust cat-back will add the same.
I just bought an K&N lookalike, and installed ($58). I avg 12 mpg so I know the pain. I was told this will add 2-3 mpg and axhaust cat-back will add the same.
I'm looking at the Volant Intake System but it's a little steep on price ($300).
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Junior User
Joined: Apr 2003
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From: Oklahoma
Gas mileage help
Originally posted by toddaz
Rich,
... however I have used several methods and found that it is off by 11 MPH...
-Todd
Rich,
... however I have used several methods and found that it is off by 11 MPH...
-Todd
Generally I would express the speed correction in terms of percent. This more accurately reflects the mileage correction of the odometer.
You must have stepped up to a much larger tire. I recently put bigger tires on my RAM. Increased the the OD about 1.5 inches and it threw my speedometer off 5 mph at and indicated speed of 70 such that I was actually driving 75 mph ( off about 7%). But when indicating 30 mph my true speed is about 2 mph off or 32.
Just trivial ramblings of an engineer.
CodyG
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New User
Joined: Apr 2003
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Gas mileage help
Originally posted by TCExp
What's the brand?
I'm looking at the Volant Intake System but it's a little steep on price ($300).
What's the brand?
I'm looking at the Volant Intake System but it's a little steep on price ($300).
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Joined: Apr 2003
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Gas mileage help
I am running 33x12.5 in my truck and my speedo is off by about 11%.
The best way to figure out by how much you are off is to:
1. Go to www.Tirerack.com
2. select a tire that comes in your stock size and the size you are running now.
3. Find the table that tells you the number of revolutions you need to run 1 mile (I think)
4. Figure out the ratio of the number of revolutions (bigger size / stock size)
Example: Stock (235x17x15) 712 revolutions/mile, 33x12.5x15 = 636 -> 636/712=0.89 -> off by 11%
Hope that helps.
The best way to figure out by how much you are off is to:
1. Go to www.Tirerack.com
2. select a tire that comes in your stock size and the size you are running now.
3. Find the table that tells you the number of revolutions you need to run 1 mile (I think)
4. Figure out the ratio of the number of revolutions (bigger size / stock size)
Example: Stock (235x17x15) 712 revolutions/mile, 33x12.5x15 = 636 -> 636/712=0.89 -> off by 11%
Hope that helps.
Senior User
Joined: May 2002
Posts: 321
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From: Hollywood, FL
Gas mileage help
I have the K&N filter and FlowMaster Cat back. I get 11 mpg in town, 17 mpg on the highway (I drive 80 on the highway). My gas mileage is probably so low because I never turn the a/c off. Sunny South Florida will make you wonder how people ever lived without a/c!
I am convinced if you want better gas mileage you better buy something else...
I am convinced if you want better gas mileage you better buy something else...
Senior User
Joined: Feb 2003
Posts: 206
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From: Long Island, NY
Gas mileage help
I recently purchased my '98 Expy w/ 96k miles from my Uncle who kept it immaculate. It has all new shocks (monroe reflex), tires (michelin xt/s) and the transmission was recently overhauled. I'm only getting 11 mpg at the most and its 90% highway miles. My question is if I unplug the battery for a while to reset the computer, could this reset help my mileage situation?
P.S. My wife drives the truck and she tells me she's not a lead foot
.
Thanks,
Phil
P.S. My wife drives the truck and she tells me she's not a lead foot
.Thanks,
Phil
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