4.88s for better MPG??? (Is there any hope?) (1 Viewer)

[HDJdreams]

I replaced a bone stock 04 TLC with a lifted an armored 13 TLC on 34” aggressive All Terrain tires.

I realize that odometer is off because of tire size, I realize that lift, weight, and tires all work against mpg, still I am surprised at how MUCH of a hit I am taking.

complaining about having to make 3 fill ups per week instead of 2 as with the 100. She is certainly not a lead foot either.

Bone stock, 200s were supposedly same or better for mpg than 100s (14/17 vs 13/18 using stricter EPA mpg test came out for 200). I have a stock 80 and an 80 that is built similar to my 200, the mpg difference between stock and built 80s isn’t nearly as great.

is also really mad that the 200 fuel gauge drops really fast after “1/2” tank and that we can’t find a distance to empty nav screen like the 100 had. We can find the screen that tells us the crappy (11 mpg) that we got, but no “trip” computer like the 100 had. Does the fuel light come on earlier than it did for 80s and 100s? It’s not my DD so I haven’t had a chance to get a feel for it.

I have a set of 4.88s and ARBs that will be going in soon. I know it will change the odometer, but is there any hope of it improving real mpg?

 

[ToyotaTrk]

doesnt apply to your model probably as mine's a 2018. but im new to Toyota so maybe you model year has it - not sure. from the manual - shows cruising range. I can also see it or distance to empty in one of the center dash menus.

 

[Markuson]

Fuel light comes on when you still have about 4 or 5 gallons in the tank.

The 200 does have a range screen, but it is the range until the light comes on...not range to true empty.

Gear will add power and easier use of 6th gear on the highway...but not likely to change mpg.

In my experience, the biggest hit to MPG comes from additional drag of bumpers, tire swingout a, ladders, etc more than simply weight. Also...from larger heavier tires.

This drag theory comes, in part, from recognizing that I stilll got 18-19mpg on the highway even when my rig was packed to the gills with gear and people...and 33’s...but before I had added external drag items.

Once bumpers and winch...swingout, fuels cans etc went on...even unladen...mpg went in the toilette.

Regearing to 4.88s will be better for your rig in other ways due to less heat and reduced reliance on your torque converter, but I wouldn’t expect a big change in mpg.

 

[grinchy]

Maybe invest in some tundra takeoffs to swap in for daily driving? Lots of 275/65r18s with rims for less than $500. Wont get you the armor weight and aero back though.
I have just a rear bumper and see 12mpg in town, so there may be no hope. I did get 16 on a recent trip with 30 miles 20mph gravel road and two medium mountain passes at 80 mph.

 

[M1911]

I would expect that adding a front bumper will significantly reduce fuel economy. Front bumpers are heavy and are less aerodynamic than the factory bumper.

Aggressive off-road tires also have significantly more rolling resistance than highway tires, and they also have significantly more rotational inertia, both of which reduce fuel economy.

Folks in Australia claim to improve fuel economy with revised transmission controllers that change how and when the torque converter locks up. Most of their experience is with the diesel V8, not the 5.7. I think that is about the only mod that might offer some limited help with fuel economy.

 

[krice118]

It would be easier to add a Cruiser brothers Long Range Fuel tank

 

[linuxgod]

I'll show you ECU-calculated mileage below on my 2013 LC with my similar build, trying to drive 80mph on flat highway for a full tank of fuel

31" OEM tires, no mod: 17.5 MPG
31" OEM tires, Gamiviti roof rack with fairing and light bar: 17 MPG
34" Nitto RGs, above rack with maxtrax and shovel added, snorkel: 11.8 MPG (about 12.5 MPG adjusted)
34" Nitto RGs, rack, Trail Tailor winch bumper: 10.8 MPG (~11.5 MPG adjusted)

The tires were by far the biggest impact on mileage. Snorkel and rack didn't seem to make a difference. Bumper was a measurable hit, as expected.

Power-wise, even when towing 6000#, the LC does fine. I've considered re-gearing in the hopes of getting back MPG as @TeCKis300 has me convinced that I'm running in a suboptimal air/fuel ratio most of the time. Others have suggested that new gears will improve mileage because you can hold 6th. I'd really like to see some semi-scientific before and after numbers from a few people with a similar setup (34"/35" tires and front bullbar) before I drop $3k on it though. I haven't done the math but I suspect it'll take several years, even if I'm towing a lot, to make back the $ spent on gears from any MPG improvement. FWIW I've heard that the Magnuson SC also improves mileage if you're light on the throttle normally but at $7k + install and the need for premium fuel it's unlikely to ever pay for itself

 

[M1911]

That’s why I took off my K02s when I got back from the LCDC and put on my highway tires. Come winter, I’ll put the K02s back on.

 

[mcgaskins]

I’ve gained a little over 2mpg with this guy, but I think the improvements are much more dramatic with the 8 speed transmission. For the low cost and easy return policy, this is worth a try: https://forum.ih8mud.com/threads/pedal-commander-or-other-throttle-controller-thoughts.1090957/

 

[Docboy]

I've come to the realization that the 200 series gets abysmal gas mileage, no way around it. No matter how much I baby this beast, whether I use premium or regular, I still get 11.x mpg in the city (lots of stop and go, hills, sudden stops due to people here who simply can not drive), and 17-18mpg on the highway (assuming flat road and consistent 65-70mph).

I could be wrong, but there's probably very little hope to improve mpg. There seem to be many ways to hurt mpg, but very little to improve it, at least significantly that is cost effective.

For those have found ways to improve mpg, please share!

 

[TexAZ]

I'm running 35s. stock front bumper, roof rack. with the stock gears I was seeing 10.5-11 around town, and right around 12 on the highway.
most highway driving here is 75-83...
I swapped to 4.30 gears. picked up .5-.8 mpg. nothing to write home about.
what did change dramatically, is the handling of the truck. the motor/trans isn't struggling as much. Breaking actually feels a lot better.
The entire drivetrain just seems to operate a lot smoother.
Towing with the gears is definitely better.

 

[HDJdreams]

@M1911 how much mpg difference do you see between KOs and highway treads? I thought the KOs were fairly mild AT (compared to the AT-MT hybrids common now).

 

[HDJdreams]

Thanks for the responses. I guess my takeaway is more surprise at how little my mods affected the mpg on my 80. Even after 33” mud tires and bullbar, I was still squeezing the factory 13/16 rating out of it regularly.

 

[TeCKis300]

Lots of variables that play into efficiency and gearing is only one of them.

Gearing would only help if the load presented to the motor at speed, is such that it has to dig deeper in its fuel map to make the necessary power. Meaning the ECU is having to enrich the fuel mixture to compensate for the added load and heat. So per unit of power that it makes, its putting in more fuel than necessary, for cooling. This wastes fuel like no other.

Recognize that gearing generally brings its own efficiency losses in the form of driveline drag and windage losses. i.e. Too much gearing, such that the motor is spinning more than necessary.

In this case for 34s, you’ll want 4.3’s.

Gearing guide here - Definitive 200-series Gearing Reference

 

[TeCKis300]

I’ve gained a little over 2mpg with this guy, but I think the improvements are much more dramatic with the 8 speed transmission. For the low cost and easy return policy, this is worth a try: Pedal Commander or other throttle controller thoughts?

Hrmm. I’m not so sure of that. I tune cars and have dialed the throttle maps directly in ECUs. This device does nothing more than make the throttle map, i.e. pedal position vs throttle body opening, more aggressive. I’ve never known a vehicle to gain mileage as a result of, effectvely being driven more aggressively. It’s plausible perhaps, if the pumping losses were such that initial acceleration is better done with larger throttle openings. For a big car like the LC, accelerating the giant mass quicker is unlikely to be more efficient than pumping losses within the motor.

 

[M1911]

@M1911 how much mpg difference do you see between KOs and highway treads? I thought the KOs were fairly mild AT (compared to the AT-MT hybrids common now).

1 to 2 mpg.

 

[mcgaskins]

Hrmm. I’m not so sure of that. I tune cars and have dialed the throttle maps directly in ECUs. This device does nothing more than make the throttle map, i.e. pedal position vs throttle body opening, more aggressive. I’ve never known a vehicle to gain mileage as a result of, effectvely being driven more aggressively. It’s plausible perhaps, if the pumping losses were such that initial acceleration is better done with larger throttle openings. For a big car like the LC, accelerating the giant mass quicker is unlikely to be more efficient than pumping losses within the motor.

Theoretical and practical applications can vary. I'm giving a first hand account with experience, so whether you believe it or not doesn't change the actual results I'm getting. Most detractors don't have experience with how differently the 16+ drives with the 8 speed transmission, but I drive the 6 speed and 8 speed 200s back to back regularly. Like I said above, this may not work as efficiently with a 6 speed because IMO it's already pretty optimized for throttle response, but it most definitely does for the 8 speed.

 

[04UZJ100]

Another thread about a modified 7,000lb brick and poor gas mileage?

 

[Taco2Cruiser]

2011 LC with 80k-110k miles, measured with separate GPS
19 mpg: Bone stock (80 mph, west Texas hills and wind)
16 mpg: Added ARB winch bar, Front runner rack, and BP 51 set to 20mm preload, 2722 rear springs, and STOCK wheels and tires
11.5 mpg: Added 295/70r17 STT Pro tires with RWs
13 mpg: Added 4.88s, BPs set to 25mm preload, 2723s rear springs
11 mpg: Modded with 6,500 pound towing in mountains
8 mpg: Modded with 9,400 pound towing in mountains

This was measures with three cross country trips, and a lot of tanks of gas to find the average.

Putting the 5.7 in the right power band is what helps lower drivetrain load, and that, uses less fuel to do the same amount of work.

 

[dryrunner]

i dropped 2 mpg just on tires, then another 1 mpg after the lift.