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1995 Gmc Yukon Tring To Get 20 Mpg.....

jamsx1

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jamsx1 Enthusiast

jamsx1

Posted
Posted

Posted some of this in another post but figured more people might read it here.

 

Ok a wait4me tune anyone got one of these for gas mileage? How about a cold air intake? My 1995 yukon with 5.7L 3:73 gets about 12 mpg on 87 octane........... I am shoting for upper teens in mpg (would love to get 20 mpg) Is this imposible? What other mods would help me achive this. Also i tow sometimes so would a hand held programer be better for me? I could just buy one of these custom deals and keep the stock computer. I would switch to a higer octane if the gains out weigh the cost. With gas over $3.00 a gallon..... even though I love it, its do or die for this truck. Any help would be great.

bryanhunt Enthusiast

bryanhunt

Posted
Posted

I don't think its possible, at some point the engine will be running really d**n lean (which would cause problems in the long run)... I mean I guess you could try smaller injectors... just doesn't sound like a good idea to me.

 

My 2005 6L gets 15-16 on summer blends and 12-14 on winter ones. 10 years more and I'm not doing that much better (I don't think the 300ml of displacement is that big of a difference).

Nytemare Senior Enthusiast

Nytemare

Posted
Posted

Get your self a 454 in there. Either it will have so much power that you will get close to your 20 mpg goal.....or it will drink so much gas that what you were getting without it will seem awesome.

 

 

in all honesty though..it will be hard. 18.something is the best I have ever heard of. Its a big vehicle. Switching to higher octane on a stock engine that is not programmed for it will do you no good as octane is designed NOT to burn. Thats why you need more octane if you have a high compression or if you have forced induction. Its to stop pre-ignition (detonation) because you can only compress the fuel so much before it just self ignites. Octane is a ratio of how much you can compress the fuel before this happens.

 

If you use high octane in a vehicle that isn't designed to burn it it will not completely burn and cause deposits on the valves, pistons and combustion chambers and these too will cause pre-ignition as they soak up fuel and ignite after the plug fires and the piston is not in the right position any more.

 

tune will help...wait4me is a good one from what I have read. get you about 2-3 MPG.

*copper electrode plugs and some good wires.

*an intake may help some.

*maybe an MSD or similar multi spark ignition. get a good distributor (if your truck has one, cant remember if 95 do or not).

*if your running aggressive thread tires, change them out for a milder street profile.

*under drive pulleys.

*If you have a clutch type fan rather than an electric unit, change it, it will give you about 1-2 mpg more and about 15-20hp.

*switch to synthetic oil would be an option but on a 95 I wouldn't as you will probably get a lot of leaks. however there is a very good possibility you have a sludge buildup so a hot oil flush at your local GM dealer wouldn't hurt anything.

*get your fuel system cleaned too.

*I run lucas fuel system treatment every other tank or so and that seems to improve mileage.

Thats about all I can think of at 10pm. Hope it helps some.

GRB60 Enthusiast

GRB60

Posted
Posted

My Wait4me tune has added about 1 MPG to my daily commuting mileage. I'm not complaining; it'll still pay for itself in about a year, and I don't mind that it goes faster if I put my foot in it. I checked before/after 0-60 times and it went .43 seconds quicker with the new tune, with no driveability issues.

 

You're not going to find 5-6 MPG in your truck, I'm afraid.

jamsx1 Enthusiast

jamsx1

Posted
  • Author
Posted
My Wait4me tune has added about 1 MPG to my daily commuting mileage. I'm not complaining; it'll still pay for itself in about a year, and I don't mind that it goes faster if I put my foot in it. I checked before/after 0-60 times and it went .43 seconds quicker with the new tune, with no driveability issues.

 

You're not going to find 5-6 MPG in your truck, I'm afraid.

17 or 18 would make me very happy

HawkeyeOC Senior Enthusiast

HawkeyeOC

Posted
Posted

You could also change those 3.73 rear end gears out to a better set of highway gears, BUT you will lose some low end performance and towing ability in the process. If you aren't towing anything really heavy it might be worth it.

Good, well thought out suggestions Nytemare!

jamsx1 Enthusiast

jamsx1

Posted
  • Author
Posted
thanks bro...not bad if I do say so my self for being awake for 17hrs...LOL

 

Yeah good sugestions! Well the ring gear would probably be good but i just rebuilt mine about 200 miles ago!

I'll problay get the tune, cai, and the electric fan..........I did that mod on my 1990 mustang gt and the results were great. About 10-15 hp on it

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