fuel mileage / 87 oct tune

[gn4u2c]

ok, Driving is getting out of control if this does not work next step is a pos 4 banger but trying to avoid that at all cost.
I hate to do this but I went all over my car in search of fuel mileage, put narrow stock tires back on, aired up to 38lbs in all tires, took rear spoiler off , removed spare jack and extra junk I had in the car, power antenna down with manual unit laying on floor works great. thinking some headlight covers will help with drag, programmed tcc to lock early in 3rd/4th now considering a low 8-10 psi boost setting, low timing 16-18* and running 87. anyone else in this boat?? my drive to work is 40 miles each way and my truck is not cutting it anymore as diesel is now 3.90 a gallon here.

 

[SHADOWII]

Could try...

having an economy chip burned?! BTW, I'm already in a4 banger!

 

[bazkook]

Feel your pain man. I used to drive a Dodge Dakota ext. cab with the 4.7L and I gave it up after having to drive out of town to go to college. Don't know what kind of gas mileage I was getting but I was having to fill up every 2 or 3 days while making 60 mile trips back and forth every day to class. Now I drive an early 90s (GASP) Toyota Camry 4 door with a 4 banger. Horrible acceleration but I have gotten 420 miles on one tank before with conservative driving. Thinking it may be a 15 gallon tank but I'm pretty sure I'm getting close to 30 MPG.

 

[scottyb]

Why not jusy keep your foot out of it and run 87? I've done this in the past, but realized that my less than 200 miles per week wasn't worth the difference in cost. With 80+ miles per day, I would certainly do it.

 

[fc227]

The commander chip has a "lean cruise" option. I use it and on long trips it helps.

You can get one at Full Throttle.

 

[pacecarta]

tt chip has lean cruise and you can have it burnt for regular fuel ,

and having a little 4cylinder is the easiest way , for me its a DSM 16v DOHC 5speed

 

[suicide six]

When you compare the diesel to a gasoline car in miles per gallon vs cost per gallon,the diesel isnt all that bad even at higher prices.But when you add the added maintenance such as 15 qts of oil,filter,additive if used etc,things kinda equal out.Get a 4 bagger rat for everyday use.Mothball the GN if need be but dont sell it.

 

[LBNJWE4]

doesn't 87 octane burn faster then 93? I always heard you get better mileage out of premium

 

[unix_punk]

+1, i have always seen better mileage on 93 as opposed to 87, seems to be worth it to just keep running 93... Just my opinion.

 

[Turbo1dr]

Have a chip burnt with a 2800 rpm limit. That should help keep your foot out of it!


This is why I enjoy my dual fuel system. I haven't bought 93 octane in over a year. It uses 87 as the cruising fuel.

 

[novaderrik]

ok, Driving is getting out of control if this does not work next step is a pos 4 banger but trying to avoid that at all cost.
I hate to do this but I went all over my car in search of fuel mileage, put narrow stock tires back on, aired up to 38lbs in all tires, took rear spoiler off , removed spare jack and extra junk I had in the car, power antenna down with manual unit laying on floor works great. thinking some headlight covers will help with drag, programmed tcc to lock early in 3rd/4th now considering a low 8-10 psi boost setting, low timing 16-18* and running 87. anyone else in this boat?? my drive to work is 40 miles each way and my truck is not cutting it anymore as diesel is now 3.90 a gallon here.

i don't think any of those things you already tried will make any noticeable difference in fuel economy. headlight covers might help a little bit, but the amount of drag from the antenna and rear spoiler adds up to almost nothing. the extra weight of the spare tire and jack is maybe 50 pounds total if you have a full size spare- and if you get a flat tire, you will realize that it is good weight to have. more timing is better for engine efficiency right up to the point where detonation sets in and causes the engine to "fight" itself, and boost is only a factor when you are getting on the gas.
the best way to get good mileage is to keep the air pressure up in the tires and drive it gently... one good thing to have is a vacuum gauge- when driving, always shoot for maximum vacuum. you'd be amazed at how much smoother you drive when you have a needle that moves with every little movement of your foot on the gas pedal. even the small movements that you almost don't even know you are doing can make the vacuum reading change by 2"-3"..

 

[turbofish38]

Everything on his list is the exact same thing GM is doing to their new Hybrid SUVs and trucks. Go to Official Chevrolet Site | 2008 Cars, SUV's, and Trucks | Chevy and read what makes the hybrid Tahoe different from the gravy sucking pig version. I use my GN as a DD and I average 20 on a 38 mile round trip. Combo of 55MPH and intown 40 stop and go. No room for getting on the boost so that helps. I'm also running a TT 93 chip. I'd guesstimate highway MPG at around 25. I dont really take it out on the interstate but maybe 2 or 3 times a year. Now I also have a 95 Roadmaster wagon and it gets 19 in town and 24 on the road. Talk about lean cruise programming. I suspect the 2.56 gears have something to do with it also.

Oh and when it's not raining and the temp is above 70 I take my Suzuki GS1000. It's good for 45MPG and 0-60 in 4 seconds.

 

[TurboDave]

When you compare the diesel to a gasoline car in miles per gallon vs cost per gallon,the diesel isnt all that bad even at higher prices.But when you add the added maintenance such as 15 qts of oil,filter,additive if used etc,things kinda equal out.Get a 4 bagger rat for everyday use.Mothball the GN if need be but dont sell it.

Not so sure I agree with that. Not at the present time anyway, because my choices are limited to my diesel Excursion which nets 17.5mpg on my daily commute (21 straight highway).
Or my GN which btw, also gets exactly the same mileage on my daily commute using the exact same route and driving style, 17.5mpg.

93 octane here now, is 3.30
diesel here now is 3.81. plus the cost of oil changes

I am driving my GN at every chance I get now (weather permitting).

 

[Adam Connell]

doesn't 87 octane burn faster then 93? I always heard you get better mileage out of premium

NO that is not true. Where that comes from is the fact that most higher octane fuels have a slower burn rate I believe it has something to do with preignition... your engine puts in the same amount of fuel regardless of fuel type unless you tell it to put less in.

I had an Exgirlfriend who's dad swore up and down that 93 gave better mpg... he said he put premium in when they went on trips... the poor goof didn't figure out that it was the highway driving doing it not the gas..

He also put it in his motorcycle which clearly stated in the book to put 87 in the tank... I guess some people just like having a lighter back pocket.

 

[gn4u2c]

I also set my intercooler scoope up to slots to lower drag, with the mods I have done so far still running 93 and 93 TT chip I picked up 1 1/2 mpg I travel the same route everytime, fill at the same place same amout of days between fills. looks like 22mpg now. If I can get it up to 25 I will let her drink the premium oherwise The cost factor may have me down on 89 or 87

I also backed the adjusters off 1 turn each out back to loosen the brake drag, I will just keep up with setting them manually

 

[TurboTnZ06]

To go bonzo nuts on it:

Remove speakers, back seat, get a lightweight battery (I use an 11 pound hawker oddesey lawnmower sized battery lol), run with only half a tank of gas, back off the fuel pressure, run fiberglass bumpers, hood, deck lid, take a hole saw to any metal not needed....