Tricks to up your fuel mileage. (V8)

Moist

Member
I've got a v8 without the valve timing thing. Usually I'm making around 14 or so mpg.

After some reading and experiment the best fuel mileage I've been able to make city driving is 16.7 MPG.

That's with premium fuel, without the spare tire, and keeping the revs at around 2,000-2,500 rpm. (That final one seems to do the trick the best)

I'm just curious now as to how far you could (in theory) push the fuel economy on the v8's.

Any techniques you all know about?
0d8cf8d7d80c61889eb23bfcf7afacca.jpg


Sent from my SM-G973U using Tapatalk
 
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I'm just curious now as to how far you could really push the fuel economy on the v8's.

Any techniques you all know about?

Check out some of the "hypermileing" forums. Most of these folks are pushing smaller cars to MPG extremes but many of their techniques could be applied to the v8 4 Runner.

As you mentioned a light foot on the gas peddle goes a long way.
Easier things to think about include:
* Avoid idling
* Pulse and glide like NASCAR/Indy drivers do when they are waiting out a flag.
* Go slower up hills, and faster down hills.
* Switching to high performance spark plugs
* Switching to a low viscosity oil or switch to synthetic oil (and ATF)to reduce friction
* Align and balance the wheels.
* Check tire pressure regularly.


Mods that I've read about include:
* Removing the roof rack, Shaving the side mirrors and door handles

* Drop weight anywhere you can tolerate it: You've already dropped the spare, other ideas... Remove sunroof and weld in a panel, remove unused seats, center console?

* Reduce rolling resistance. Find skinnier tires and lighter rims. If you have the sport with larger brakes switch to the smaller calipers/ brakes.

* Custom light weight "skid plates" with a golf ball texture that smooth out the bottom of the rig streamlining the airflow.

* Fender skirts covering much of the rear tires.

* Inflatable "trailer tails" that smooth out the airflow and reduce suction behind the rig.


Boort
 
Mine gets pretty crappy around town mileage, around 14 but highway only its a bit better like 16-17mpg. The bigger tires actually help bring the rpm down. And yes keeping your rpms low everywhere you drive is the best for mpg.
 
I didn't calculate my trip but my GF and I did a trip up to Smugglers Notch in VT last weekend and my 4runner did pretty well on fuel. I filled up at the local gas station down the street before we left and got there with 1/2 a tank left. My '08 v8 has a 2.5-1.5 lift and nitto terra g2's. It's about 169 miles from my house to the resort. I consider that pretty well for the miles, up and down mountains and the way the 4runner is built.
 
I've got a v8 without the valve timing thing. Usually I'm making around 14 or so mpg.

After some reading and experiment the best fuel mileage I've been able to make city driving is 16.8 MPG.

That's with premium fuel, without the spare tire, and keeping the revs at around 2000 rpm. (That final one seems to do the trick the best)

I'm just curious now as to how far you could really push the fuel economy on the v8's.

Any techniques you all know about?
0d8cf8d7d80c61889eb23bfcf7afacca.jpg


Sent from my SM-G973U using Tapatalk


Hate to be the bearer of bad news but the dash display is notoriously unreliable and typically indicates significantly better numbers than you're getting. On my V6 for example, I've calculated the MPG at every fill-up for over 25K miles through the Fuelly app, which does miles traveled divided by gallons burned (the only truly accurate method). The average is 17.2 whereas the dash display, even after being reset multiple times, always comes back to 19.7.

I've often wondered where the dash panel gets its numbers. Anyone know?

As others have noted, there's not much magic to be done in terms of V8 MPG improvements. In fact, this reminds me of the discussion about improving the V6's performance. In both cases, these engines are solid, reliable, and durable, and it's best to just accept them for what they are b/c money spent trying to make them something else is a waste.
 
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The dash mileage calculator is from the last time you reset it. If you want to get true mileage, fill the tank and note your miles. Drive until you are at 1/4 tank, fill it up, subtract starting mileage from current mileage and divide the result by the fill up gallons. If you want the dash calculator to do it, press the reset and drive for 3/4 tank then check it.

I pull a 6,000 lb. travel trailer and get 9-11 mpg depending on the headwind. If I don't reset the calculator then that factors in when I'm not pulling it.
 
We also have a very early (in our case, 2003) V8, as well as a 2009 V6.

There's no way you can rely on that fuel mileage computer, it's hopelessly optimistic! Our V8 gets 10-12 around town, and 15-17 on the highway. The lower end of that is in the winter, when gas is blended. (These are actual calculated #s over several tankfuls).

But don't feel too too bad; the V6 isn't that much better. It gets 14-16 around town and 19-21 on the highway. One thing that I will say is that the VVTi V6 pulls almost as hard as the non-VVTi V8. Still, the V8 does sound worlds better, even through stock pipes.

One thing that absolutely saps mileage is AT tires. We used to have normal all-season tires on the V8 and on a long summer highway trip I once achieved 19.7 mpg, calculated. But I never came close to that after we got new AT tires.

I don't think the spare tire should ever be left home ... it's not enough weight or drag do make a noticeable difference! If/when you need it, you'll sorely regret not having it!

Also, I would not bother with premium fuel. Our V8s are very mildly tuned, with very un-pushed timing; as such, there's no need for high-octane gas. That's just lighting money on fire.







I've got a v8 without the valve timing thing. Usually I'm making around 14 or so mpg.

After some reading and experiment the best fuel mileage I've been able to make city driving is 16.8 MPG.

That's with premium fuel, without the spare tire, and keeping the revs at around 2000 rpm. (That final one seems to do the trick the best)

I'm just curious now as to how far you could really push the fuel economy on the v8's.

Any techniques you all know about?
0d8cf8d7d80c61889eb23bfcf7afacca.jpg


Sent from my SM-G973U using Tapatalk
 
I’d be hard pressed to believe that anything extreme done to try and improve mpg being worthwhile money wise at the end of the day.. I tried the whole premium gas thing and.. yea.. sure . You may pick up a bit better mpg but you still end up spending a lot more per fill up so other than running premium you don’t gain anything at all.

If you’re to the point of welding in the sunroof, shaving down mirrors and handles, and taking out the console and unused seats than maybe an early 2000s V8 suv just isn’t for you ..


Sent from my iPhone using Tapatalk
 
We also have a very early (in our case, 2003) V8, as well as a 2009 V6.

There's no way you can rely on that fuel mileage computer, it's hopelessly optimistic! Our V8 gets 10-12 around town, and 15-17 on the highway. The lower end of that is in the winter, when gas is blended. (These are actual calculated #s over several tankfuls).

But don't feel too too bad; the V6 isn't that much better. It gets 14-16 around town and 19-21 on the highway. One thing that I will say is that the VVTi V6 pulls almost as hard as the non-VVTi V8. Still, the V8 does sound worlds better, even through stock pipes.

One thing that absolutely saps mileage is AT tires. We used to have normal all-season tires on the V8 and on a long summer highway trip I once achieved 19.7 mpg, calculated. But I never came close to that after we got new AT tires.

I don't think the spare tire should ever be left home ... it's not enough weight or drag do make a noticeable difference! If/when you need it, you'll sorely regret not having it!

Also, I would not bother with premium fuel. Our V8s are very mildly tuned, with very un-pushed timing; as such, there's no need for high-octane gas. That's just lighting money on fire.

I'm rocking Bias Ply Trailer Tires year round until I can get new rims, that's also the reason I no longer have a spare. Those old rims and tires are pretty aged. I'll take that to mind when I eventually get new ones.

Also, I really didn't know that about the fuel, nice to know though. 100$ to fill up 20 gallons for the good stuff. Definitely will save the bank.


I have also yet to try this new driving style on the interstate. If I made almost 17 city, then I want to see it on the interstate. Holding 2,500 is the v8's spot for best mileage.
 
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I’d be hard pressed to believe that anything extreme done to try and improve mpg being worthwhile money wise at the end of the day.. I tried the whole premium gas thing and.. yea.. sure . You may pick up a bit better mpg but you still end up spending a lot more per fill up so other than running premium you don’t gain anything at all.

If you’re to the point of welding in the sunroof, shaving down mirrors and handles, and taking out the console and unused seats than maybe an early 2000s V8 suv just isn’t for you ..


Sent from my iPhone using Tapatalk

I am aware, just curious to what people do for better mileage is all.
 
Hate to be the bearer of bad news but the dash display is notoriously unreliable and typically indicates significantly better numbers than you're getting. On my V6 for example, I've calculated the MPG at every fill-up for over 25K miles through the Fuelly app, which does miles traveled divided by gallons burned (the only truly accurate method). The average is 17.2 whereas the dash display, even after being reset multiple times, always comes back to 19.7.

I've often wondered where the dash panel gets its numbers. Anyone know?

As others have noted, there's not much magic to be done in terms of V8 MPG improvements. In fact, this reminds me of the discussion about improving the V6's performance. In both cases, these engines are solid, reliable, and durable, and it's best to just accept them for what they are b/c money spent trying to make them something else is a waste.


I'll see if I can get one of my mechanic buddies to take a look at the system and see if he can figure it out. He's got the tools to reprogram the whole thing so I'll ask.

Sucks though that it's so off. makes sense though, when I first got the car it gave some bizzare readouts. oh well.

I'm used to the normal mileage, just curious though what some people do or the theoretical maximum someone can get.
 
I'll see if I can get one of my mechanic buddies to take a look at the system and see if he can figure it out. He's got the tools to reprogram the whole thing so I'll ask.

Sucks though that it's so off. makes sense though, when I first got the car it gave some bizzare readouts. oh well.

I'm used to the normal mileage, just curious though what some people do or the theoretical maximum someone can get.

As far as real-time (vs. average), I had my OBD reader plugged in during a road trip. Cruising at 55 mph on a perfectly flat stretch of interstate, the instant MPG readout in the OBD Fusion app was a consistent 23.7. The average will never be anything approaching that but I was surprised it was up that high. Of course, if you watch the instant readout through such an app, you see anything from <5 mpg (accelerating up a steep hill) to 70+ (coasting down the other side).
 
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Been driving mine around without the rear driveshaft lately, identifying as a Honda :rofl: Basically busted the cap off the slip yoke while greasing it and I have a plan to weld it back in place just haven't gotten around to it.

Will report back if mpg improves in front wheel drive :eyebrows:
 
Hi all. Just a note -- I bought a 2003 v8 and did the following to it right after purchase: new engine air filter (it was really old), new cabin filter, red line ignition cleaner, and cleaned the Mass Airflow Sensor.

These things together allowed me to achieve 24.5mpg (according to the dash computer) over 40 miles on the highway going 55mph in a very flat area with no wind. According to the error that I've seen on the onboard computer, this should easily have put me above 21mph which is not bad at all! But with any wind and higher speeds, the computer usually holds around 20-22mpg (so realistically 17-19mpg). My most recent trip (with wind, hills, higher speeds, several stops) had a confirmed 17.7 mpg highway via odometer calculation.

City has been around 15-16mpg. I did ride behind a semi-truck on another stretch and got the computer up to 25.5 mpg but that was a fluke from drafting hah.

Other than cleaning the MAS (which is very easy, < 5 minute job), make sure your tires are inflated. If you're doing highway driving you can just pump them to the max rating which will reduce rolling resistance at the cost of traction (which shouldn't matter if you're on pavement).
 
I've got a v8 without the valve timing thing. Usually I'm making around 14 or so mpg.

After some reading and experiment the best fuel mileage I've been able to make city driving is 16.7 MPG.

That's with premium fuel, without the spare tire, and keeping the revs at around 2,000-2,500 rpm. (That final one seems to do the trick the best)

I'm just curious now as to how far you could (in theory) push the fuel economy on the v8's.

Any techniques you all know about?
0d8cf8d7d80c61889eb23bfcf7afacca.jpg


Sent from my SM-G973U using Tapatalk

I was getting about 14-14.5 mpg, then I started using non ethanol fuel.. before she died she was showing 17.5 give or take..
 
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