MPGs - Many People Griping - A Foundational Knowledge Primer To Assist in Better Efficiency

[COSmurf]

One common misconception is that lc 4cyl provides better gas mileage at highway speeds than the Lexus gx
Accordin to car and driver 75mph highway testing they both averaged 21mpg
So much for its a harsh 4 cyl , well atleast it delivers on fuel economy

https://www.caranddriver.com/lexus/gx#:~:text=Fuel%20Economy%20and%20Real%2DWorld,economy%2C%20visit%20the%20EPA's%20website.

https://www.caranddriver.com/toyota/land-cruiser-2026#:~:text=The%20EPA%20hasn't%20released,economy%2C%20visit%20the%20EPA's%20website.

https://www.caranddriver.com/toyota/land-cruiser-2026#:~:text=The%20EPA%20hasn't%20released,economy%2C%20visit%20the%20EPA's%20website.

The Car and Driver test flat out says they hold the car at 75 MPH… the fuel consumption at that speed will not be all that different between GX and LC for all the reasons stated previously. The small LC motor can just employ enough boost to deliver the power of a much larger motor like the GX’s. Drop down to 70 or 65 MPH and the fuel consumption between LC and GX at those highway speeds is drastically different. As I said, think of the turbo and hybrid as displacement on demand. The neat party trick however cannot be done in reverse by the GX where it sheds displacement (and pistons) to be anywhere near as efficient as the LC motor because at its baseline, it’s a much larger motor even when driven gingerly. I love that the LC can step up and power the car to near GX levels of HP and Torque for bursts as needed, but then is much more gas efficient the rest of the time. That’s a really nice feature and attribute to possess. The GX engine is way more thirsty for the rest of the time. I also love that the LC achieves that big power not solely through employing more boost, but also incorporating hybrid electric boost so as to not stress the engine as much as would be the case if it went to max boost pressures of say 20-25 without electric vs the 10-15 with electric it runs at.

 

[robsurfskate]

then you don't get overdrive on the highway

then you don't get overdrive on the highway

Hmmmmm. I did not know that. NORMAL driving mode on highway will get it in the higher gear ratio?

 

[robsurfskate]

then you don't get overdrive on the highway

Thanks for the heads up. I need to be in NORMAL mode for highway driving.

 

[GrayBeard]

The Car and Driver test flat out says they hold the car at 75 MPH… the fuel consumption at that speed will not be all that different between GX and LC for all the reasons stated previously. The small LC motor can just employ enough boost to deliver the power of a much larger motor like the GX’s. Drop down to 70 or 65 MPH and the fuel consumption between LC and GX at those highway speeds is drastically different. As I said, think of the turbo and hybrid as displacement on demand. The neat party trick however cannot be done in reverse by the GX where it sheds displacement (and pistons) to be anywhere near as efficient as the LC motor because at its baseline, it’s a much larger motor even when driven gingerly. I love that the LC can step up and power the car to near GX levels of HP and Torque for bursts as needed, but then is much more gas efficient the rest of the time. That’s a really nice feature and attribute to possess. The GX engine is way more thirsty for the rest of the time. I also love that the LC achieves that big power not solely through employing more boost, but also incorporating hybrid electric boost so as to not stress the engine as much as would be the case if it went to max boost pressures of say 20-25 without electric vs the 10-15 with electric it runs at.

This is spot on.

There's a reason high performance piston engine aircraft (at their pinnacle think end of WW2) almost universally used superchargers or turbo/superchargers. Weight. As much as we worry about MPG, for aircraft engine size and weight were killers, so getting more out of an engine by forced air induction on demand was so crucial as to be essentially mandatory.

In my growing experience with the LC the key factors that don't compete so much as intertwine for better MPG are absolute speed and consistency of speed.

So far my best tank MPG has been just over 26 MPG, and that was prior to the first break in oil change. My MPG on average has continued to just go up as I close on 5K miles. That 26 MPG was from a string of very fortuitous commutes during spring break, which meant much less traffic on the roads and a steady cruise speed be it on the highway or city streets (my 25 mile one way commute is about 50/50 though I can bias it depending on traffic). I was still in the break in period and didn't exceed 65 mph at all on that tank, and was generally at 60 mph on the freeway and 35-45 on the city streets, but essentially never had to slow and accelerate for traffic and made most lights.

Now I still try to keep at or below 70 on the freeway as I've experienced much better MPG at 65-70.

But I just did the first road trip last weekend even though it was short. About 2 hours up, 2 hours back, and if you've ever driven I-64 from Hampton Roads to Richmond you know that it's slow and go for a good portion even without accidents and traffic, but also that if you're doing less than 70 in the right lane when it's "go" you're going to get run over, rear ended, shot, or some combo of the three. So I averaged between 70 and 80 on the way up with normal slow and go and still got about 24 MPG while the trip back had stop and go behind two accidents but still got about 23 MPG.

On individual stretches (10 miles or more) where I could hold a steady 65 or 70 I was flirting with 28 MPG on the gauge, so I fully believe it's doable. I should note that all of my commuting is done alone, but on the trip I had four adults and 9 year old in the car, so solo my numbers would have been marginally higher I believe.

On the flip side, this morning's commute was almost zen like, hitting almost every single light green and free flowing traffic on the highway portions, and my trip average climbed up to 25.2 MPG with city driving at about 40 mph. So having the turbo to boost performance (no pun intended) lets the LC work like a larger engine on the freeway, but a smaller engine on the street.

Still loving the LC.

And the one bad light I did hit this morning, just as it went red, is two minutes long. But being a hybrid the engine shut down and I didn't use any gas, plus the guy in the LX 460 next to me got to ask how I liked the LC because he was thinking of getting one.

 

[Viktorv1961]

Not buying it from car and driver. I can get 29 MPG highway cruising at 65 MPH. Doubt the GX can do it.

The LC iforce max hybrid is a fantastic drive train if you know how to use it. Then you can just take the GX MPG and add +8 MPG.

There are many sources in this forum and beyond that discuss how to achieve it.

All stock LC LC in "Normal" mode. I cannot get even close to 29MPG. Last week I purposely drove at 64-67 mph on 100 miles round trip. As a result-22.1 MPG. But I can get about 27-28mpg on country roads driving about 50 mph.

 

[SlickLC]

eco mode did net me more mpgs on local roads under 55. i was averaging 16-17mpg in normal mode and 17-19 in eco mode. gonna have to do more testing on highway.

 

[Blue Sky]

I have an anecdotal observation regarding the adaptive cruise control, distance spacing and a potential effect on MPGs.

I did a 2k out-and-back through the midwest a few weeks back. I used the adaptive cruise control for around 95% of the interstate driving. What I noticed is the distance setting regarding vehicle spacing seems to have an impact on MPGs.

At the ACCs maximum distance setting (4 blue bars) the LC held a more controlled speed while using almost no braking and minimal throttle to maintain speed. When traffic increased or I was passing through city centers I set the bars to 1 or 2 to decrease spacing between vehicles. While the ACC did an exceptional job at maintaining the distance, I noticed the brakes were being used quite a bit and then throttle/turbo was being applied to compensate for over correction. Multiply this brake/accelerate cycle by the tens to 100s over the course of a trip and I can see a mpg penalty adding up.

 

[BlueCruiser]

Keep trying! It is definitely possible to achieve 29 mpg's on the highway. I did it at sea level on flat terrain in normal mode without much difficulty. The LC had 20 inch OEM wheels and a crossbar but otherwise unmodified.

Below is a summary of information that may be useful if trying to maximize fuel economy.

Background
First, It helps to understand the design philosophy as described by Toyota because the I-Force Max 2.4L hybrid is different than traditional combinations of twin turbos, superchargers, hybrids, or AWD EVs. It uses a standard inline four cylinder turbo as the ICE, mated to a standard 8 speed transmission (less gear searching vs a 10 speed), and with an electric motor (EM) sandwiched in between.

This combination has produced the highest power, highest torque, and highest fuel economy ever in this class of its vehicles (LC and Taco). Other than the electric system, it leverages standard, well proven, and readily available light truck components for the engine, transmission, drive train, suspension, and brakes. It also has the promise of extending the longevity of the vehicle because it has fewer moving parts, and reduces the load on the ICE, transmission, and braking systems over its useful life. Only time will tell.

It is important to understand this architecture because in order to maximize performance the driving technique is counter intuitive. For fuel economy, it should be operated as a very low revving four cylinder vehicle rarely going above 2K RPMs. To do this, the driver must focus on leveraging the electric engine and induce its use as much as possible. Some call this "pulse and glide". Others describe it as driving by RPM vs MPH. Either way, the objective is use the electric engine more and the ICE less.

Driving tactics
1. The electric motor can sustain speeds up to 15mph on its own. RPM is zero and electric sound hums.
2. The EM can solely maintain speeds up to 30mph on its own. Once at speed, RPM drops to zero and electric sound hums. Soft pedal the accelerator so the ICE never kicks in.
3. The EM can sustain highway cruising speeds up to 65 mph while keeping RPMs within the peak torque 1700 to 1800 range using the pulse and glide technique. This gives rapid power delivery and forces the EM to provide the boost rather than revving the ICE or spooling the turbo. RPMs remain constant yet you feel the boost/pulse of the EM to push faster.
4. Just a note. Although not moving, I have noticed the vehicle can run the AC and other systems for a relatively long period of time while parked before the ICE kicks in temporarily and then shuts of automatically. This saves quit a bit of gas compared to other vehicles that must sit there and idle the whole time.

When people complain that they are driving 75 mph and getting lower than expected MPG it suggests they are thinking about it backwards. For those who would complain that it is too much trouble to think about and just want to drive the vehicle, remember that this philosophy will keep you constantly in the optimal power band (about 1800 RPMS) and provide the most rapid power delivery. In sport mode, it is a total blast.

By understanding how this very clever and capable system was designed and re-training your driving instincts it is amazing what can be achieved for both fuel economy and driving performance. I fully expect someone with a little time and practice can break the 30 mpg barrier soon.

Good luck

 

[Ike582]

I've hit 26mpg on two trips thus far. One was a 250 mile highway drive where I averaged 65-70 mph.

The second was an hour of bumper to bumper highway traffic heading to downtown Chicago. I was shocked by the high mpg on the second drive, until I realized that the LC was using only battery power for much of the trip. The engine was basically off and a light application of the gas pedal kept me in the crawl of traffic.

 

[RideWithYanu]

I have an anecdotal observation regarding the adaptive cruise control, distance spacing and a potential effect on MPGs.

I did a 2k out-and-back through the midwest a few weeks back. I used the adaptive cruise control for around 95% of the interstate driving. What I noticed is the distance setting regarding vehicle spacing seems to have an impact on MPGs.

At the ACCs maximum distance setting (4 blue bars) the LC held a more controlled speed while using almost no braking and minimal throttle to maintain speed. When traffic increased or I was passing through city centers I set the bars to 1 or 2 to decrease spacing between vehicles. While the ACC did an exceptional job at maintaining the distance, I noticed the brakes were being used quite a bit and then throttle/turbo was being applied to compensate for over correction. Multiply this brake/accelerate cycle by the tens to 100s over the course of a trip and I can see a mpg penalty adding up.

That’s a great observation, and it actually reflects what traffic engineers describe with terms like car-following theory, headway management, and the fundamental diagram of traffic flow. When cars follow too closely, small speed changes turn into waves of braking and accelerating that spread backward through traffic, a phenomenon called capacity drop. This doesn’t just hurt fuel economy but also makes congestion worse overall.

Put simply, leaving more space between you and the car ahead lets you drive more smoothly without constantly hitting the brakes or throttle. That saves fuel because your engine isn’t working overtime to keep adjusting. It also helps everyone else on the road by preventing the chain reaction of stop-and-go driving. Your anecdote about using adaptive cruise control on its widest setting is a perfect example of headway management working as intended. It’s not just better for your MPG but for the whole flow of traffic.

I’m not a traffic engineer, just a massive nerd who finds obscure topics like this one fascinating and research-worthy.

 

[GrayBeard]

Keep trying! It is definitely possible to achieve 29 mpg's on the highway. I did it at sea level on flat terrain in normal mode without much difficulty. The LC had 20 inch OEM wheels and a crossbar but otherwise unmodified.

Below is a summary of information that may be useful if trying to maximize fuel economy.

Background
First, It helps to understand the design philosophy as described by Toyota because the I-Force Max 2.4L hybrid is different than traditional combinations of twin turbos, superchargers, hybrids, or AWD EVs. It uses a standard inline four cylinder turbo as the ICE, mated to a standard 8 speed transmission (less gear searching vs a 10 speed), and with an electric motor (EM) sandwiched in between.

This combination has produced the highest power, highest torque, and highest fuel economy ever in this class of its vehicles (LC and Taco). Other than the electric system, it leverages standard, well proven, and readily available light truck components for the engine, transmission, drive train, suspension, and brakes. It also has the promise of extending the longevity of the vehicle because it has fewer moving parts, and reduces the load on the ICE, transmission, and braking systems over its useful life. Only time will tell.

It is important to understand this architecture because in order to maximize performance the driving technique is counter intuitive. For fuel economy, it should be operated as a very low revving four cylinder vehicle rarely going above 2K RPMs. To do this, the driver must focus on leveraging the electric engine and induce its use as much as possible. Some call this "pulse and glide". Others describe it as driving by RPM vs MPH. Either way, the objective is use the electric engine more and the ICE less.

Driving tactics
1. The electric motor can sustain speeds up to 15mph on its own. RPM is zero and electric sound hums.
2. The EM can solely maintain speeds up to 30mph on its own. Once at speed, RPM drops to zero and electric sound hums. Soft pedal the accelerator so the ICE never kicks in.
3. The EM can sustain highway cruising speeds up to 65 mph while keeping RPMs within the peak torque 1700 to 1800 range using the pulse and glide technique. This gives rapid power delivery and forces the EM to provide the boost rather than revving the ICE or spooling the turbo. RPMs remain constant yet you feel the boost/pulse of the EM to push faster.
4. Just a note. Although not moving, I have noticed the vehicle can run the AC and other systems for a relatively long period of time while parked before the ICE kicks in temporarily and then shuts of automatically. This saves quit a bit of gas compared to other vehicles that must sit there and idle the whole time.

When people complain that they are driving 75 mph and getting lower than expected MPG it suggests they are thinking about it backwards. For those who would complain that it is too much trouble to think about and just want to drive the vehicle, remember that this philosophy will keep you constantly in the optimal power band (about 1800 RPMS) and provide the most rapid power delivery. In sport mode, it is a total blast.

By understanding how this very clever and capable system was designed and re-training your driving instincts it is amazing what can be achieved for both fuel economy and driving performance. I fully expect someone with a little time and practice can break the 30 mpg barrier soon.

Good luck

View attachment 42537

I've observed this though you explain it better than I could.

As an example, my LC doesn't "like" the band between 45 and 50 MPH. I routinely find myself at or above 2K RPM if I accelerate into that band. But if I push through it and then back off to 50 MPH the revs drop and the fuel efficiency goes back up.

 

[mrCharlie]

I noticed MPG went down a little when I aired the tires down to the correct pressure (33 cold), from around 35-36. I just bumped them up to 34.5 trying to figure out a random cold-start Adjust Pressure issue, so I'll see if that makes any difference in MPG.

I've also noticed I lose a few MPG when I have the Kuat rack/mountain bike on the back, at least a bit more than I've noticed on other vehicles. Could just be that the MPG gauge is per trip and tank small so I see the impact more.

 

[pizzlegreet]

This is an interesting thread.

One thing that I have noticed is when I drive by those signs that tell you your speed it always says that I am driving a few mph’s slower than my speedometer. Also when I have Apple Maps or Google maps open, each app says that I am driving 5% slower that what my speedometer quotes. This makes me wonder if the MPG that is calculated by me LC250 is also 5% over.

I haven’t timed my odometer yet using the mile markers in the freeway but that’s next on my list of todos for checking this.

If the LC250 is in fact off then I am not getting the advertised mileage, changing my oil too soon, and running my odometer up. I’m in a lease so I will end up paying for extra mileage at lease end, etc.

My LC is stock—wheels, tires, everything.