If you look at my mods you can see my car inst to gas mileage friendly, but on my last trip i took a 350 mile trip and after 256 miles i had to refill because my gas light came on came out to 18mpg. It was constant cruising on cruse control at 65mph and 2186rpm or so. I just used 1/3 a can of seafoam and have run many Lucas engine treatment almost every tank. I just rolled over to 83k on my 2000 and was thinking maybe i should change my spark plugs? I never haven't owned my car that long so i don't know if they need to be changed or not. How easy are they to change? Also should I use the whole can of seafoam? I sucked it through the iac. What about a fuel filter should i change that? how easy are they to change any special tools needed? Also could i yield better mileage if i drive at 75mph which is about 2500rpms?
Question about tuneup and gas mileage
- Thread starter mat82284
- Start date
96GTstang46
New Member
Yea i would do the fuel filter. its pretty easy. Its right behind and above the gas tank.
The spark plugs are pretty easy too.. just some basic tools, and a little bit of your time. I would say if you take your time maybe 45min to an hour for both.
Also i have 4.10's and still get 21-22mpg for some dumba** reason, but then again i dont gun it hella.. its my D.D so i kinda have to baby it.. lol only till summer...
But maybe try cruzin at 70mph, but dont think its going to make any difference. If so, let me know.. lol
The spark plugs are pretty easy too.. just some basic tools, and a little bit of your time. I would say if you take your time maybe 45min to an hour for both.
Also i have 4.10's and still get 21-22mpg for some dumba** reason, but then again i dont gun it hella.. its my D.D so i kinda have to baby it.. lol only till summer...
But maybe try cruzin at 70mph, but dont think its going to make any difference. If so, let me know.. lol
I usually average right out at 20mpg. Between your roush kit and all the heavy sound stuff you got, it might just be enough to get a little worse MPG than most people. My absolute best MPG was on a 200 mile trip, going about 60mph the whole way and very very light on the pedal and it came out to 28 - 29mpg but I dont know if both gas stations clicked off at the same point when I filled up. I've never gotten this kind of mileage again, but it drove me nuts to keep it at 60mph for like 3 hours.
Fuel filter and plugs are a good idea, but I dont know if it will make that big of a difference. The plugs are rated to 100k but most people arent comfortable waiting that long. I changed mine close to 90k and it drove the same. You'll need the quick disconnect tool for the fuel filter.
Fuel filter and plugs are a good idea, but I dont know if it will make that big of a difference. The plugs are rated to 100k but most people arent comfortable waiting that long. I changed mine close to 90k and it drove the same. You'll need the quick disconnect tool for the fuel filter.
Dusstbuster
I love meat more than anything! I just have a spec
If you want the absolute best gas mileage ever, then NEVER turn on your stereo while you drive, and NEVER use any HVAC controls either, always shift below 3K, and you should bet set. 
Really, fuel filter and plugs should help, I know my filter change got me about 1-2mpg increase. Are 99+ cars different than 96-98 as far as filters? I bought the fuel line removal tools for my filter change 2 years ago and it didn't even need them.
Really, fuel filter and plugs should help, I know my filter change got me about 1-2mpg increase. Are 99+ cars different than 96-98 as far as filters? I bought the fuel line removal tools for my filter change 2 years ago and it didn't even need them.
Just my experience , and YMMV, but the best "mod" I did in the last couple years was ditching my horrible stinky platinum plugs ( with 50K on them) , and going to a copper core plug. Car runs smoother, and +2 MPG, as well. The platinums are designed for people who don't like changing plugs (99% of drivers, apparently, since the service intervals are 100K).
I use a long extension, and a wobble joint, and I pay attention to torque (low, 10-15). I used anti-seize on the threads the first time, and didn't last time. Your choice. One more thing - you should use a shop vacuum to suck out the spark plug recesses after you unplug the COPs, and BEFORE you remove the plug. There may be some crud and dirt down into the well, and you don't want that crud in your cylinders.
Get your car in the best running condition possible to maximize mileage.
Use scientific methods to ascertain you mileage, many people do not do it right and get flawed data.
Remember that the a/c compressor runs in all positions except the ones to the immediate left and right of OFF. Do not use a/c unless you have to.
Only use top tier gas.
Use scientific methods to ascertain you mileage, many people do not do it right and get flawed data.
Remember that the a/c compressor runs in all positions except the ones to the immediate left and right of OFF. Do not use a/c unless you have to.
Only use top tier gas.
You might not be calculating your mileage correctly.
Could this affect gas mileage?
Yes and yes. Play it safe and assume they have not been changed.
No.
well i just wanted to say thanks to everyone that replied, Can you tell me what spark plugs i need and what i should gap it to? do i need the socket swivel or is that just to make it easier? Also i have a spark plug socket i believe its 3/4 is this the correct size for our plugs? as for the fuel filter should i buy this at Ford? or will a Kragen model or napa model do just fine?
Motorcraft AGSF-32C @ .054
Makes it easier...
Spark plug socket will work. Remember to remove the rubber sleeve on the inside for the plug install or the socket may stick to the plug in the well.
Buy it at the Ford parts counter and get a 2007 Ford Racing Performance Parts catalog while you are there.
Also, changing plugs sounds easy but there are a thousand ways to do it better and make it go smooth. I have posted them too many times to post them again. Do a search...
Check out the Bullitt Archive article on fuel filter change also.
hotdog71
Member
NGK TR55IX
Are these better than the stock spark plugs???? should i buy these instead? Also if i go with the stock ones. I was told i should go 2 steps colder because i have many bolt ons. I also live in CA with all the hot weather. Do you guys agree? And if so which model plugs am i looking for? because if i ask ford they would give me the stock ones.
What speed do you drive at on the freeway 65mph?
40th GT
New Member
Colder plugs aren't necessary unless you have forced induction or nitrous. I assume you are N/A, so stock heat range should do. Or if you're really anal about this, you can get 1 step colder plugs for the 2 cylinders that are closest to the firewall. These cylinders don't receive as much cold coolant as the ones up near the radiator, so they tend to run hotter than the others. Therefore, gettin colder plugs for those cylinders will prevent detonation.
Check out this website, www.bullittarchive.com for detailed instructions on how to perform Mustang maintenance.
As far as mpg goes, sticking to the speed of traffic/speed limit gets you the best mileage. Remember, the less throttle you apply, the less fuel the engine uses. RPM is not really related to mpg.
ok well i just bought me some tr55 NGK spark plugs and im getting ready to install but ive never installed spark plugs on a 4.6 only a 5.0 where are the spark plugs at? i dont see them near the headers? Also what do i gap these plugs at?
Plugs are under the coils. There are 8 coils, 1 for each cylinder. You'll see them next to each fuel injector. Unplug the connector, pull the 8mm on the coil and pull it out. Some can be a real PITA to pull out because they can get a little stuck.
Gap was listed above (.054). If you got the motorcraft plugs from Ford for your specific application, there is no need to set the gap.
Alright thanks guys and for anyone else looking for instructions i found them just like kilgor trout said
http://www.bullittarchive.com/WebHelp/BullittArchive.htm#Welcome.htm
http://www.bullittarchive.com/WebHelp/BullittArchive.htm#Welcome.htm
Finished changing the spark plugs and had pick up a package from ups put about 30miles on my car and my gas gauge barely moved. My old plugs were so black and dirty, They looked like the ones that were born with the car hahah. Anyways the car idles so much better and has better acceleration. Thanks guys!
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