MPG? FYI. Why Your Tacoma Gets What It Gets

Beautiful opener in this thread @hiPSI

Logical and well put together. Definitely needed right now.

 

One morning while snowmobiling in ma. we came across an abandoned honda cr-v stuck in the middle of the trail. We called the local club that grooms the trail. They dragged that little suv so far into the woods off the trail that they will need a crane to lift it out.

 

@hiPSI Great post with relevant information. Happy with my 2020's MPG. I knew this going into this. Compared to my 1992 Extra-cab 3.0L 5sp 4X4 my 2020 seems like the Fat Elvis. These trucks have grown over the years.

 

This is the information I'm here for

 

Good read! Good job op

 

16 mpg. Fiberglass shell, decked system, tire swing gate, add a leaf, at tires.

 

I wonder if the chin strap reduces the HP to 56 down from 57 on the highway

 

It could, I do not know for sure. I did calcs on total frontal area of the Tacoma. When it comes to angles and curves and drag, you need true simulation programs and a wind tunnel or two.

 

Not reading through 11 pages to see if this has been mentioned already, but in response to the original summary, I feel you hugely simplified some of the trickier tricks manufacturers use to get better mpg.

Most of this is in maximizing the (in)efficiencies of the Otto cycle by increasing dynamic compression ratio through things like EGR, variable geometry cam lobes (VVT), and modest turbo-sourced compression - not just embracing an Atkinson cycle. Ie: Cruising on a flat highway: why not turn off 2 cylinders and increase effective CR from 9.5:1 to 12.5:1? Combustion engine efficiency is fundamentally limited by 2 things: temperature difference, and compressability.

This is why diesel engines are more efficient in comparison: high piston compression and ability to increase that multiplicatively with forced induction.

Final note: we may not have regenerative braking, but we can still coast to a stop as much as possible to more fully utilize that energy we put into the system.

 

i wonder if lightweight, aluminum wheels would help with mpgs. i bet the oem steel wheels are heavy as hell. i bet lightweight wheels would make a massive difference.

 

I weighed my steelie spares (without tires) to check on this as @crashnburn80 felt they would be significantly heavier than alloys. They were heavier but IIRC it was more like 1-2 lbs per wheel difference. Enough that you'd want to get alloys but not so much that it's a terrible idea to run steelies.

Granted that's the stock toyota 16" steelie and other steelies might be different. I weighed four of them, some slight variations but they were reasonably close.

 

guess lightweight wheels may not be worth the price if it's only a couple pounds difference.

 

Depends on what you are comparing to though. A heavy 16” FJ alloy wheel at 28lbs IIRC, or a light 16” TRD OR alloy wheel at 23lbs. Of course there are many other advantages to alloys such as superior strength and they won’t rust. Minimizing rotational weight will improve MPG, acceleration, braking and reducing unsprung weight improves handling and ride, all on a relative scale of course.

 

Good bump. I like the Ridgeline. I have a 2nd gen 4x4 tacoma in great condition and a 2021 Pilot which feels like the perfect situation. But if I was to own one vehicle it would definitely be a Ridgeline.

 

You forgot gearing, which is extremely important, and they really missed on these. The tranny does not keep the truck in the powerband where it should be, and the final gearing is already too high. Add weight and bigger tires and that issue is really pronounced. I don't care as much about the MPG as the power and delivery.

 

drove home with ECT on last night, really kept the RPMs in the powerband unlike normal mode. got 28 mpg on my drive home. I would get 20 mpg without ECT mode on. seems you can actually get better mpgs with ECT mode if you can drive with a light foot.

 

I dislike cylinder deactivation. I feel that it not only creates a weak point, but one that will be an expensive fix. Forced induction, I am all for. I like the newer vehicles that can detect octane and adjust timing/boost to allow you to run lower octane fuel as needed.

 

Deactivation does nothing but make the other active cylinders work harder, putting them into a more efficient region of their BSFC plot. (generally around 2500rpm, 80% load is most efficient)

 

Know your audience. If you want to come over to the physics forum I frequent then this post would be much different.