Need MPG opinions

[northsnoma]

After replacing the fuel filter,plugs,wires, and thermostat im still getting 14 mpg highway . Anyone have any other ideas? No SES light and cap/rotor replaced not long ago

[HenryJ]

Not sure where you are from? Sounds about normal for winter grade fuel.

[northsnoma]

I'm from Michigan, totally forgot about the winter blend aspect haha. Suppose if its as good as itll get I'll quit with the tune up stuff then and move one to upgrades!

[HenryJ]

You are going to be hard pressed to improve mileage above the window sticker. 15 mpg city and 19 mpg highway are what mine said. You can do a few little things to improve performance, and hopefully maintain reasonable mileage. Let it breathe. Opening the exhaust is the best bang for the buck.
Look around and see what makes sense to you. I was very happy with the performance mine had.

[northsnoma]

Well I'm not even getting window sticker mileage for highway and this is what I was worrying about. I've gone on two 160 mile trips recently, both 98% highway and averaged 14-15mpg. If its because of the winter blend than thats fine I realize this vehicle is not the most fuel efficient. My meaning of this posting was not to figure out how to gain extra mpg just as a means of determining if everything operating correctly because I thought a steady 14 was rather low for highway mileage compared to the specs I'm really looking forward to working on it this summer, opening the exhaust and the Mystery lift, blast some rust and tackle the rusted out crossmember in front of bed... got me drooling!

[killian96ss]

I average about 16 mpg in my 05 ZR2. That is 14 mpg city & 18 mpg hwy combined. My 01 Crew Cab was exactly the same. Make sure your tires are aired up to the recommended air pressure or a little higher for extra mpg's & try some good injector cleaner next time you fill up.

Steve

[northsnoma]

Okay will do. What is the recommended pressure? PO removed the sticker
Thanks for your help Henry the search works wonders but sometimes its nice to have some live feedback ya know

[HenryJ]

Tuning pressure for street use:

Tuning pressure for street use is not too difficult of a task. Learning to adjust your tire pressures for the different terrains you wheel on is a great tool to have. The correct pressure on the street is required as it ensures long tread life, decent ride quality, and predicable handling. Pressure at either extremes on the street will cause issues. Pressure too high and you'll wear the center of the tread off the tires very quickly and this will also produce a jarring ride. Pressure too low and the tires will build up heat, this will kill the tire quickly and cause adverse and unpredictable handling. Many people look at the rated pressure on the side of the tire and assume that is the running pressure, ITS NOT. The pressure listed on the sidewall is usually maximum pressure. Do not exceed the max pressure.
Here is a comon procedure for finding the correct street pressure for your tires.


Find and empty parking lot.

Inflate your tires to the max pressure listed on the sidewall.

Mark the tires across the tread with a piece of chalk or crayon whatever really.

Drive straight forward several feet, be sure not to turn at all.

Look at the mark across the tread and see which part of mark has worn off.

If the mark has worn off at the center but not at the edges you have too much pressure (duh i already told you max pressure would be too much). Drop the pressure and repeat steps 2-5 until the desired pattern is achieved. Be careful too low of a pressure will rub the mark so always start with too much and work your way down. Loading will play a large roll in your quest for the perfect tire pressure. Normally the front will be slightly more loaded than the rear as a result of the positioning of the engine, likewise a fully loaded rig ready for 2 weeks in the woods may balance that out and require more pressure in the rear then normal. Atmospheric pressure and temperature play roles too. Changes between the seasons can effect optimum tire pressure. A 10 degree drop in temp will drop your cold tire pressure by 1 psi. Most tires will lose about 1 psi per month due to porosity of the rubber compound in the tires and slight leaks at the bead. Also altitude makes a difference pressure will increase slightly with a gain of altitude due to the reduced atmospheric pressure. Final determination of proper tire pressure is seat of the pants, go test drive it and play around for a while.

** If this method will not achieve the correct pattern you have selected the incorrect tire width/ wheel width combination.**

[killian96ss]

With 31's I usually run about 35 psi on all 4 tires. 40 psi will get you better gas mileage, but the ride starts to get a little bumpy and squeaks will get more noticeable. When I had my CC I liked 36 psi front & 33's psi rear.

Steve

[LoneWolf04]

I would make sure you don't have any worn front end parts causing unnecessary drag. Does the truck drive straight? Even a bad alignment will make mileage suffer. Also, when you did the cap and rotor, did you make sure that the screens in the bottom of the distributor were removed? Those tend to clog up and hold moisture in the cap area and corrode it out faster than salt kills your sheet metal.

I'm in michigan as well and have been getting 15-16mpg and that is with a 50/50 city/freeway driving. Normally in the winter an all freeway drive for me means 17-18 keeping it at 70mph on the freeway. Keep my tires at 33psi and have stock sizing, but they are pretty aggressive tread, GoodYear DuraTracs.

[HenryJ]

...Also, when you did the cap and rotor, did you make sure that the screens in the bottom of the distributor were removed? Those tend to clog up and hold moisture in the cap area and corrode it out faster than salt kills your sheet metal.

Our housings are plastic and don't have the screens like the older aluminum housings. We do have holes, but they are baffled with a half closure at the top one way and the opposite on the bottom. Compressed air to clean them out works.
Watch those screws and read the plastic distributor warning.

[LoneWolf04]

My '02 has the baffles in it, but it still had screens on the inside that I removed upon doing a cap and rotor change after purchasing the truck. Only had 60k on it and it's the original distributor.

[HenryJ]

News to me. I have seen more than half a dozen plastic distributors and none with screens. Mine was 2001 and the one I have on the shelf is from a 2004.
The TSB that came out and the manuals describe screens, but they also show aluminum housings from the old 4.3L engines. I guess if you got'em, pull'em. If you don't... you don't

[northsnoma]

I will check for screens tomorrow. Yes an alignment is needed there is a slight pull to the right. Had an SES come up a while ago before the tune up that read: random cylinder misfires, something related to new thermostat (replaced), and front left wheel bearing needing replaced (sensor was not liking the signals it was receiving?). Did the tune up, thermostat, and check wheel bearings with the tire play test and seemed ok, was the same as the right side. Since then SES light has not come back on. Could their still be an issue happening and the SES light not coming on? I've noticed what sounds/feels like a slight stumble at idle even once warmed up. I feel like my mpg is an indicator that somethings just not right

[DLP]

I am in Mi. too. I get 17 to 19 with 80% hiway at 75MPH. I did a backwoods 55/60 MPH trip from Lansing to Cadalic and back a couple weeks ago.Headed to a couple lakes ice fishing. I got 19, 20 and 20.5 MPG on 3 fillups. I keep records of every fillup. You can see that I start loosing MPGs about mid November every year. Not sure if it is all about the mixed gas, or that I let the truck warm up more.

[northsnoma]

Ya thers definently something up with my truck then. i know my vacumn system is polluted with the dreaded atf. gonna fix that when it warms up. seems to be a slight stumble at idle once warmed. I think i need to clean/replace idle sensor and O2's i suppose. gona perform cat back as well

[04crewvt]

Remember also those window stickers were set to reflect the average MPG on unleaded gas not the Ethanol blend we all are forced to run now. That alone dropped about 1/2MPG from my truck when i could no longer get straight gas. I am in Northern VT and I average 14.7 or so in the winter mixed city/highway.

[HenryJ]

Remember also those window stickers were set to reflect the average MPG on unleaded gas not the Ethanol blend we all are forced to run now. ..

Very true. My experiences have been that the mileage is reduced 10% I have easily lost 1.5-2 mpg across the board on the vehicles that I have checked.

[roadrunner]

I have done numerous tests with the last 10 or more vehicles I've owned. In ALL cases the across the board MPG loss is a consistent 8% on 10% ethanol blend gasoline. I've also tried numerous times to run Premium Regular and the MPG gains have always been insufficient to offset the increase in price over regular. BTW my crew gets 18-21 highway warm weather dry pavement and 14-16 in town warm weather dry pavement mileage since that's what this thread was originally about. On road severe mud/snow/cold weather conditions that figure drops as low as 8 MPG. It is fairly consistent at 13 MPG on muddy but somewhat passable roads in average temps.

[northsnoma]

I have done numerous tests with the last 10 or more vehicles I've owned. In ALL cases the across the board MPG loss is a consistent 8% on 10% ethanol blend gasoline. I've also tried numerous times to run Premium Regular and the MPG gains have always been insufficient to offset the increase in price over regular. BTW my crew gets 18-21 highway warm weather dry pavement and 14-16 in town warm weather dry pavement mileage since that's what this thread was originally about. On road severe mud/snow/cold weather conditions that figure drops as low as 8 MPG. It is fairly consistent at 13 MPG on muddy but somewhat passable roads in average temps.

Ya the weathers been pretty cold and windy, that and the ethanol/winter blend must just be how it is. filled up today and calculated 13MPG over the last 164 miles (city with proper warm up time). Guess whenever i'm on the highway the trucks pretty packed and always a strong headwind to bring my mileage down

[rlrnr53]

If I let my truck warm up when it is cold, my milege usually drops to between 9 and 13 MPG. Since I've been running longer trips, i"ve been getting between 15 and 17.5 MPG.

[northsnoma]

Forgot about this thread, turns out my intake gasket was shot and had to buy a new distributor. Pieces were laying inside of the housing, I'm not even sure how it was still running Havnt calculated mileage yet since I've been riding my motorcycles from April on, but will have a fair amount of miles spent in the truck this weekend

[Torskdoc]

I took my 02 to a reunion in Branson from Baltimore 1st week of may. Avg spd 62(this is where she settles and runs best), no A/C, all interstate. Just me, a weeks worth of clothes, Laptop, and about 100# of necessary tool's. 1st fillup in Morgantown was 17.5 (appalacians). Subsequent fillups were all between 25 and 26 mpg. I kept the vacuum gauge tagged @ 12-13 inches while cruising on flats and slight upgrades and let speed drop. downhills I kept 17-18 inches and let speed build up. I put a can of Seafoam in the tank @ start of trip and again at start of return trip. trip avg was 25.62mpg for return trip. total trip avg of 25.34 and approx 2400 miles. Normal driving around town is about 15-17. Winter mpg goes down to about 14 city and 22 highway. Mine has a modded ECU by Waitforme, and upgraded transmission pistons, electric fan, 5W-30 Synthetic. No exhaust mods, tires, etc.

Wife is now driving it as we have a 95 Jimmy and she doesn't like the Jimmy.

It likes relatively flat open roads for mileage. Hills kill the mileage as the Rev's with a 3.42 aren't high enough to put the cam in the sweet spot for power. Mine apparently is off the cam below 2000rpm. @ 59 mph it's right @ 2000rpm. Below 2K and I have to keep more throttle in to maintain speed. I can see this in the vacuum gauge also. Below 60 I'm using 9-11 inches to maintain speed in OD. Above 60 it shows 13-15 on flat to maintain speed up to about 65mph then I have to use more throttle and less vacuum. Engaging the Cruise control and maintaining 62, the C.C. will throttle to 8-10inches to maintain speed on flat, where I can foot it to almost 15 inches and maintain speed. (so much for "progress"!!!!).

Larry