5.0 AWD fuel economy

[masospaghetti]

96 4-Door XLT, 5.0/AWD, 151,000 miles.

Please don't bother saying stuff like "you shouldn't have gotten a V8 if you wanted good fuel economy". I understand this will never be a hybrid, but when I'm currently getting 13-17 mpg, any gains will save a considerable amount of fuel.

I've already done a full tune up and full synthetic fluids (oil, diff, trans, TC). Tires @ 35 psi. I've gotten between 13 (city) and 18 (highway). I feel like I should be able to get at least 20 on the freeway. Just wanted opinions on the following:

1. Tuning - are the programmers worth it for a stock motor? For power, and/or fuel economy? I used a SCT tune on my 4.0 OHV and honestly didn't notice any difference.
2. Oxygen sensors - I think they are original, but I have no drivability symptoms or check engine codes.
3. E-fan - seems like a lot of work.

Thanks everyone!

 

[bill06447]

EPA ratings were 12/17 and that's before 18 years of wear and tear. Clean the MAF sensor in the air cleaner housing. New O2 sensors might help a little but I think it will be a lot of driving before they even start to pay off in fuel economy gains, if any.

Bill

I should add, 150 pounds of extra crap in the back is like driving with a passenger all the time. Jettison the extra oil, washer fluid, etc and leave the third seat in the garage, if you have one and don't usually need it

 

[masospaghetti]

I keep the vehicle pretty clean, so no extra oil or coolant in the back.

I've thought about ditching the spare tire and bottle jack but it doesn't seem worth it for the ~50 lbs of savings. I'm curious how much weight, if any, an alloy rim is compared to the steel rim that I currently have as the spare.

 

[koda2000]

My personal experience:
2001 Eddie Bauer 5.0 RWD 186k 15-16 in town, best HWY 23, worst ever mpg 13's. 2000 Mountaineer 5.0 RWD 190k (same mpg as '01 EB. 2000 Mountaineer 5.0 AWD 165k about 1 mpg less than RWD's on average. I don't have to deal with much traffic, drive conservatively, but live in a hilly area.

All 3 vehicles are very well maintained, use Mobil 1 full synthetic oil, have Michelin LTX M/S2 tires, which are kept at 32 PSI.

IMO, tuner's work well for diesel engines but aren't worth much for gasoline powered vehicles. Your O2 sensors are a bit overdue to be changed. They can make a big difference on fuel economy. I think it's only the front 2 (upstream) sensors that can effect fuel economy. If you run your finger inside your tail pipe does it come out sooty? If so, you're wasting fuel and I'd start with changing your O2 sensors.

 

[jremington59]

You're doing good with the mileage you are getting. You're doing as good as I am with my 97 and I added the cold air intake. My 2000 gets better highway mileage for some reason.

96 4-Door XLT, 5.0/AWD, 151,000 miles.

Please don't bother saying stuff like "you shouldn't have gotten a V8 if you wanted good fuel economy". I understand this will never be a hybrid, but when I'm currently getting 13-17 mpg, any gains will save a considerable amount of fuel.

I've already done a full tune up and full synthetic fluids (oil, diff, trans, TC). Tires @ 35 psi. I've gotten between 13 (city) and 18 (highway). I feel like I should be able to get at least 20 on the freeway. Just wanted opinions on the following:

1. Tuning - are the programmers worth it for a stock motor? For power, and/or fuel economy? I used a SCT tune on my 4.0 OHV and honestly didn't notice any difference.
2. Oxygen sensors - I think they are original, but I have no drivability symptoms or check engine codes.
3. E-fan - seems like a lot of work.

Thanks everyone!

 

[1998Exp]

Actually, the EPA ratings (at least as shown on the original window sticker of my '98 5.0 AWD) were 14/18. Got about 5% below these numbers when the truck was fairly new. Now, at 155K it's about 10%-15% below. I don't drive it enough these days to justify putting a lot of effort into this challenge.

EPA ratings were 12/17 and that's before 18 years of wear and tear
...

 

[crunchie_frog]

You may want to consider reducing your speed during highway driving. At 55 mph, during repeated tests, I got~23.5 mpg. At 70 mph I got ~ 19.7 mpg. Also, running lowering your oil viscosity to 5w20 if you are not already running it will give you another ~0.5 mpg. (Ford recommends the 5w20 by the way).

 

[MAS Tequila]

00 5.0 AWD bone stock

13 around town and 19-20 on the highway if I keep it under 70mph.

MT

 

[bill06447]

Actually, the EPA ratings (at least as shown on the original window sticker of my '98 5.0 AWD) were 14/18.

EPA was forced to revise them several years back, as they were a bit inaccurate and, um, misleading.

I think driving style has a lot to do with mpg. I'm an easy driver, light on the gas and brake, anticipate stops/starts, don't let the vehicle warm up for a half hour, stay close to the speed limit, the fuel lasts a bit longer in the Explorer when I'm driving than when my gf drives it.

Bill

 

[delexploder]

Swap out the 3:73 rears for 3:27s

 

[SoNic67]

Swap out the 3:73 rears for 3:27s

OP has an AWD. Your suggestion won't work.

 

[delexploder]

Duh, notice I said rears, change both, at our shop we have been thinking about what MPG would be, the 5.0 has enough torque to still take off ok, just picture turning 1500 rpm at hwy speed!

 

[SoNic67]

Well, on HW I get 19-20mpg with mine. I think it is not the internal friction (rpm) that counts that much, but air resistance against a brick shape traveling with 75mph.

I think the issue is the city driving, stoplights and such. You need to accelerate a 2 ton vehicle from zero to 45mph. No matter how you do it, you need to burn the fuel to provide that kinetic energy.
For the numbers above, that's approx. 400 kJ. Gasoline (E85) energy density is some 25MJ/L - 94MJ/gal. Efficiency of a steel block gasoline engine is around 0.35-0.37.
That gives around 82 starts from 0 to 45mph per each gallon of fuel.
Every time your city adds a stop light in your path, your gas mileage will drop.

Actually, accelerating slowly will burn more gas because you spend more time in lower gears, with TC not locked. Acceleration should be somewhere around 2800-3000 rpm (not lower, not higher, that's the optimal rpm for acceleration) until you get to speed limit (or 5 above in my case). Then keep it constant so the TC will stay locked.
And while waiting for the red light to change, put the transmission in "N". It will stop spinning that oil inside the TC (called stall mode).

 

[h0und10]

Well, on HW I get 19-20mpg with mine. I think it is not the internal friction (rpm) that counts that much, but air resistance against a brick shape traveling with 75mph.

I think the issue is the city driving, stoplights and such. You need to accelerate a 2 ton vehicle from zero to 45mph. No matter how you do it, you need to burn the fuel to provide that kinetic energy.
For the numbers above, that's approx. 400 kJ. Gasoline (E85) energy density is some 25MJ/L - 94MJ/gal. Efficiency of a steel block gasoline engine is around 0.35-0.37.
That gives around 82 starts from 0 to 45mph per each gallon of fuel.
Every time your city adds a stop light in your path, your gas mileage will drop.

Actually, accelerating slowly will burn more gas because you spend more time in lower gears, with TC not locked. Acceleration should be somewhere around 2800-3000 rpm (not lower, not higher, that's the optimal rpm for acceleration) until you get to speed limit (or 5 above in my case). Then keep it constant so the TC will stay locked.
And while waiting for the red light to change, put the transmission in "N". It will stop spinning that oil inside the TC (called stall mode).

I agree completely about accelerating faster.. i got laughed at when i mentioned that in a similar thread on here but its true.. the faster you get to 4th gear the better..

 

[jremington59]

I wish there were an easy way to take a thousand pounds off them, lol.....

 

[h0und10]

I wish there were an easy way to take a thousand pounds off them, lol.....

and chop the top so its not so poorly aerodynamically designed

 

[J_C]

and reduce the load carrying capacity, get rid of the AWD option, reduce tire weight, get rid of the spare tire and rear seat, reduce the amount of glass, make it narrower, shorter, smaller gas tank and cut the number of wheels in half so it's a motorcycle.

There's nothing worthwhile that can be done to an otherwise properly running 18 yo vehicle with 150K miles except keep it running and drive something smaller for fuel economy and to avoid putting too many more miles on it so it is still running for the times when you really need an SUV.

Otherwise you wear it out, have to start over and decide again about smaller economical car vs larger gas guzzler.

 

[SoNic67]

Well, the weight has it's advantages...
In an impact with another vehicle, the one with larger mass gets the lower deceleration (g forces). That's usually good for the internal organs
I see my higher gas bill as an insurance against bodily injuries. Like any insurance you might not use it ever. But you don't want to be without it...

 

[masospaghetti]

My personal experience:
All 3 vehicles are very well maintained, use Mobil 1 full synthetic oil, have Michelin LTX M/S2 tires, which are kept at 32 PSI.

IMO, tuner's work well for diesel engines but aren't worth much for gasoline powered vehicles. Your O2 sensors are a bit overdue to be changed.

Thanks for the bit on the tuner, I won't bother.

EPA was forced to revise them several years back, as they were a bit inaccurate and, um, misleading...the fuel lasts a bit longer in the Explorer when I'm driving than when my gf drives it.

Bill

Totally agree about the gf, mine does the same thing.

Anyone know why the EPA ratings improved in 1999 for the V8? From 12/17 to 13/18?

I'm going to go ahead and put in new oxygen sensors, they are not expensive ($56 for both). I'm curious how much, if any, they help.

 

[koda2000]

yeah, when my daughter complains about the fuel economy on her '00 AWD, i remind her of the comfort, utility & safety it offers, how she doesn't have a car payment, has a low insurance bill, hardly pays anything in advolorum tax and get free maintenance and repairs (from me). all those savings pay for a lot of gasoline. when she's worn it out, she's welcome to buy a Honda Fit (ugh), or whatever, if she wants great fuel economy.