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How to get more miles per gallon?

Bigburban

Bigburban

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Anybody experimented with changing out resisters to see if you can get more miles per gallon? I have a #7 #5 #3 resisters. Would changing from the #7 to the #3 increase mpg by decreasing fuel or would it take something else with it? I don't do any towing with the suburban. Any input would be helpful.
 
The resistors only make minimal changes to max. fuel delivery. Your right foot will determine your mileage.
 
What's your rear differential ratio and what's your current mpg, city and hwy?

I have no idea what the resistors do, but everyone says to use #9.
 
Would also be good to know how it is driven, how many highway miles daily ect... and what kind of boost you are getting when accelerating and when cruising.
 
Only about 14-25 miles per day maybe 5 of that highway. Set about 9 lbs of boost max at wot. Boost about 3-6 average driving. Boost at 70mph about 4-5 4.10 gears. Average city about 12-16 hwy about 18-20
 
Not sure you can get much better that what you got and if that amount of driving is worth spending more money. By your sig looks like you already upgraded to later model cone filter box. A reflash is spendy, but a optimized timing curve could net you some little better mileage in the city. You running dual 195F T-stats? The warmer it runs, like around 200F, the better it might do in town. Skinny tires and lite aluminum wheels might help but a good chunk of change for new wheels. The obvious upgrade to 4" exhaust, and if you havent done new mandrel bent downpipe and crossover it will help with constant stop and go acceleration.
 
Bigburban said:
Only about 14-25 miles per day maybe 5 of that highway. Set about 9 lbs of boost max at wot. Boost about 3-6 average driving. Boost at 70mph about 4-5 4.10 gears. Average city about 12-16 hwy about 18-20
Click to expand...

Seen 18 on the highway with the '95, never 20. 12-14 city driving is pretty much the norm. We'll see if there's a change when we purchase and install the ATT.
 
You could either install a 3.42 in the pumpkin or even easier just find a junked rear end with a 3.42. After that, I don't know I'd worry about it. I don't go over 70 mph but if you have time on your hands, keeping the rpm down while cruising may increase performance some but I consider my time more valuable than what I'd save. In fact, I don't think there's much you can do that's cost effective to produce legitimate fuel economy gains beyond the pump elimination you've done.

Try driving a 3.42 geared 6.5. You might find it more relaxing to drive when the engine isn't working so hard at cruise.
 
Dan Hunter said:
You could either install a 3.42 in the pumpkin or even easier just find a junked rear end with a 3.42. After that, I don't know I'd worry about it. I don't go over 70 mph but if you have time on your hands, keeping the rpm down while cruising may increase performance some but I consider my time more valuable than what I'd save. In fact, I don't think there's much you can do that's cost effective to produce legitimate fuel economy gains beyond the pump elimination you've done.

X2
Go with synthetic fluids front to back might get you a mile or 2. The way the 89 held up, really sold me on synthetics.
800,000 on the rear differential - never touched. About the same on the transmission. The engine looked clean inside. Nobodies ever tore it down to see what actually locked it up.
I was going to put the new timing chain and gears out of it in my 94 but apparently I left them in the truck or misplaced them. That's $200+ I'll never have back

Try driving a 3.42 geared 6.5. You might find it more relaxing to drive when the engine isn't working so hard at cruise.
Click to expand...
 
The 3.42s might not help much in town off the line, where a lower gearing might be an advantage since it takes less time and fuel to get to speed. Although getting cruise speed down helps and maybe just some slightly taller tires would do enough. A couple inches taller on the tire would drop it a tick or two on the tach. New wheels time is also not a bad time to find some used 18-19" aluminum wheels or whatever that will be lighter rotating mass.
 
3.42s suck in the city. i know because thats what i drive mostly. hard any torque at that low of rpm. i got 16 mpg twice when i drove like a grandma for half a tank but it got old. i usually get 15.2-15.7 mpg. ill see what my new mpgs are after i install the reflashed computer from kojo i have been patiently waiting for.
 
NVW said:
The resistors only make minimal changes to max. fuel delivery. Your right foot will determine your mileage.
Click to expand...

I agree.

Resistors make a change to the fuel delivery to keep the pump withing spec due to manufacturing tolerances. #9 means a weak pump or will up the fuel on a good pump. It is an emissions thing.

Your foot controls the amount of fuel into the engine. It will override resister choice as you press the pedal more to get that tank moving. Less fuel with smaller resister, you go slower - overcome by pushing the go pedal. I doubt you would even notice the resister change.

Otherwise

Keep it below 55.
Get a smaller rig.

Your short drive time hardly warms up the engine.

Look at cost vs. benefit before you invest in MPG. It may cost more for better MPG widget than you will save in fuel. Short trips and total miles per day make it hard to justify the $ of MPG improvements.
 
I run a 9 resistor, see sig for more details.

We live in hilly terrain, but driving style is mostly your control factor.

If you don't want to switch to synjthetic lubes, try Lubrilon. I went up 2 MPG AVERAGE.

Just my $0.02
 
I usually just hook a chain to a semi that's going the same way I am. It dramatically improved my mileage from 19/20 mpg hgwy to about 80/81 mpg.
I don't recommend this for the weak hearted or if you want your marriage to survive, also when the trucker finally figures out you hooked a ride on his truck he will usually
(a) ask for fuel money, which wipes out the fuel mpg. you just saved.

(b) pulls a gun and threatens to blow your head off.

(c) shakes your hand and says (man that takes balls you're a braver man than me), and then shares the story with his friends on the CB while you make a quick getaway before he changes his mind and comes back looking for (AorB).

But seriously if you get 18/20 mpg. your doing alright.

Towing 5000lbs. I avg. 16/17 depending on grade and doing 75/80 mph. I think that's pretty good for a 6000lb truck and 5000lb trailer.

These trucks aren't VW TDI that get 45/50mpg. My burb out tows the tahoe I had and gets better mpg. towing than the tahoe did DDing with nothing in tow.

Hope you atleast get a chuckle out of my sick sense of humor
 
Thanks for the input sounds like I am getting all the mpg that I can. It still does alot better than the Yukon I had with the 5.7 lucky to get 8-10 driving the Yukon around. I will try the synthetics. The burb has just now broke into 20,000 miles. Just completly rebuilt the rear end so no changing that. I am going to put bigger tires on it when I get a chance I have heard several people say it helps lower the rpms any where from 200-400 rpm.
 
Taller tires will help, so dont go too wide, you just want a higher ratio which is the second number. Like 265 would probably be as wide as you want to go, with a sidewall ratio of 75 percent, so 265/75/16. Although I would recommend taller aluminum wheels like 18/19" if you want taller tires to maintain the passenger vehicle handling, plus the stock steel wheels are really heavy, like twice as heavy each wheel, at least it seems that way trying to carry them around. Dropping unsprung rotating weight helps efficiency in stop and go. You might be able to find a set for like $200 used.
 
i am running a set of 235/85/16 BFG Commercial T/A, they fill up the wheel wells nicely and no rubbing on my 2500
 
The 3.42's really hurt on the hills where i live. Has a lot more grunt now than it used to with mods. On the highway my truck will run almost 19 empty. But i hardly drive on highway. Now i have a Jeep Grand Cherokee (I-6) as another D/D, and it gets 16 around home, and 20 on the highway. Plus its gas, and right now gas is a good .33 cents cheaper than diesel.
 
That is about the mileage I got with my suburban. My suburban is similar drivetrain as yours except it is a 95.
 
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