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1st Time Pontiac Owner, How to Improve MPG???

S

Suspect

New member
Hello, so I own a 2005 Honda Pilot with 89k that my wife drives, and a 2014 Ford Focus ST with 15k that I drive. I also recently picked up a really well maintained 2001 Pontiac Grand Prix GT with 83k that I will be using to commute about 80 miles/day pretty much all highway. I really like it and have driven but never owned a pontiac.

I've been browsing this forum for a few days and there is good info here for sure. I'm fairly active on the focusst.org as well as radar detector forums as I'm a Rd geek :)

Anyhow, since I'm only commuting highway I was hoping you guys could chime in on the best ways to max out mpg. Is there a specific tune/calibration I can buy (the cheaper the better), how have people done with k&n filters? Or whole intakes? Over inflating tires? I'm guessing a tune will be the most beneficial but does anyone sell one specifically for economy? Thanks on advance!
 


your best bet is to find a local tuner that can tune it in car. besides that keep up on your maintenance and it will do well. I recently heard a theory that a vehicle is the most efficient when the most vacuum is present, so based on that you could get a scan gauge and see what speed creates the most vacuum and then set your cruise control.
 
Interesting. Yeah I've started looking at tuners and it seems they are mostly all for performance, so I guess I'll just have to drive like grandma. I tend to have a lead foot so I like the idea of a tune helping me drive more conservatively.

As far as tune ups, the folks that had the car before did the plugs about 20k ago but the shop didn't put the heat shields back over the plug boots. I ordered them to put on but since the wires are right next to the headers should I be worried about the heat the boots have been exposed to for the last 20k? I am thinking I should order new wires and maybe even plugs.
 
I wouldn't worry about the heat shield boots, they don't do that much anyway. When you get your car tuned for performance they should also do a few things to help the fuel economy
 
Suspect said:
Interesting. Yeah I've started looking at tuners and it seems they are mostly all for performance, so I guess I'll just have to drive like grandma. I tend to have a lead foot so I like the idea of a tune helping me drive more conservatively.

As far as tune ups, the folks that had the car before did the plugs about 20k ago but the shop didn't put the heat shields back over the plug boots. I ordered them to put on but since the wires are right next to the headers should I be worried about the heat the boots have been exposed to for the last 20k? I am thinking I should order new wires and maybe even plugs.
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The tuners for these cars are not just for performance. There are many settings in the pcm that affect fuel efficiency.

I would start with these items just to ensure that everything is nice and fresh. Most of these items should help with your fuel economy.


  • New oil and filter
  • Drop trans pan change filter and add new fluid - DO NOT DO A TRANS FLUSH
  • New OE wires
  • New Ac Delco 41-101 plugs gapped @.060
  • New fuel filter
  • New air filter
  • Coolant flush with green coolant - get rid of the Dexcrap
 
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Slick2500 said:
The tuners for these cars are not just for performance. There are many settings in the pcm that affect fuel efficiency.
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But are you talking about the full custom calibrations or the plug and play pcm units? for $120-180 I would be interested but if I'm understanding what I'm seeing on like www.zzperformance.com the full tuner software and a handheld tuner (that I don't know how to use) is around $500. Or you mean finding a local tuner who can do it for a one time fee?
 


I wouldn't buy a plug and play pcm from any of the vendors if all you want to do is increase your fuel economy. I would either try and find someone local who knows how to tune GM vehicles for better efficiency or buy a used DHP Tuner, they can usually be found used for about $250 or so.
 
A tune just for mpgs isnt worth the cost. And you likely MAYBE see difference in 1-2 mpgs, if that.

If you can avg 28-30 mpgs all highway with a full tune up, thats about the best you are going to get. You may at times over 30-32 but the overall avg tends to drop slightly.

Also anything over 65-70 mph and the mpgs tend to drop, in a GT car you are already pushing 2100ish rpm and at 75+ you are just using more fuel with 2400-2500 rpm.
 
Yeah I've been keeping it to 70 to hopefully optimize mpg. I think I'm going to buy some oem plug wires just in case some of the boots got baked. And maybe new plugs as well. Has anyone had any noticeable differences running a high end spark plug?
 
Anything else kinda just doesnt work. They only like Iridium plugs or copper core plugs.

The waste spark ignition system eats platinum plugs alive and anything like a E3 plug is pure junk.

Copper plugs only last 15k miles roughly but the stock iridium ac delco plugs are 75-100k miles and are the best overall.
 


Fivefingerdeathpunch said:
Anything else kinda just doesnt work. They only like Iridium plugs or copper core plugs.

The waste spark ignition system eats platinum plugs alive and anything like a E3 plug is pure junk.

Copper plugs only last 15k miles roughly but the stock iridium ac delco plugs are 75-100k miles and are the best overall.
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Okay perfect that's really good info thanks, not sure what they put in when they did them last time but carfax says the new plugs were not put in at a dealership so I wouldn't be surprised if they were non oem.

Seems these motors really like oem stuff.
 
Another thing.. these motors have torque and they are fun to push the pedal. A lighter foot at take off and changes in speed will help tremendously.

No..it's no damn fun.. but you can get your mpg up just by changing your driving style.
 
i find i get great mpg when the car sits parked for days on end. i get back in and its like oh yeah! i got a full tank still lol
 


camopaint0707 said:
sell, get a honda
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I found put recently that I get better gas milage than a 5-speed Honda del sole. Lol. Its all about the anti-lead foot. If I try hard I can get it down to 12mpg but I drive back roads and get 28 or so. Good enough for me.
 
so another question then, does anyone advise against running a full synthetic oil? I was thinking of switching to Mobil 1 extended performance oil/filter and going 10k between changes, since I do all highway with this car. Do you guys run full syn? blend? is there a forum favorite oil?
 
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