Good place to get started ? want to get at lest 40-45MPG.highway.

[AeroMcAeroFace]

Originally Posted by Isaac Zachary

I do believe there's only one way to get +40mpg permanently out of this vehicle. An EV conversion. If it's a hybrid you apparently already have half the parts to do it. Next step would be to fill the vehicle up with more batteries. (It'll be heavier, which is what you want anyway, right?) Add a way to charge them and figure out how to cheat the system so the ICE won't turn on. And Violà! A 45mpg-e vehicle!

I agree but the original post said "times are tough and it's 3.99 a gallon here" batteries would be so expensive that it wouldn't be worth it. If the poster wants american cars then the Chevrolet Volt easily gets at least 40-45mpg on the highway.

The tahoe is worth $10 000 - $15 000 according to autotempest ads in california and a base model Volt is currently for sale in california for under $10 000. Sometimes the best mod, is a car swap.

Less likely to tip over, newer, better MPG, lighter, safer in a crash. Isn't a prius, fits all the criteria Tahoe_Hybrid mentions.

https://www.cars.com/vehicledetail/d...paign=atempest

Originally Posted by aerohead

You know where the engine's BSFC sweet spot is. If all efficiency gain is to come at 45-mph, and only from aero drag reduction, then, after streamlining, the Tahoe's gearing must be such that is absolutely matches the load you're seeing now, keeping it on the same BSFC pounds per brake horsepower-hour island, perhaps requiring a Gear-Vendors overdrive unit if you can't find a ring and pinion tall enough.

But the weight of the vehicle and rolling resistance means than 40MPG is pretty much impossible, even if aero drag was zero (obviously impossible), but even if the aero drag was zero, the maximum mpg according to the calculator is 42MPG https://ecomodder.com/forum/tool-aero-rolling-resistance.php?Weight=2500&WeightUnits=kg&CRR=.015 &Cd=0&FrontalArea=20&FrontalAreaUnits=ft^2&FuelWh= 33557&IceEfficiency=.22&DrivetrainEfficiency=.95&P arasiticOverhead=0&rho=1.225&FromToStep=5-200-5
I agree with what you say aerohead about regearing, I am just disagreeing on the practicality in this specific case.

[aerohead]

Originally Posted by AeroMcAeroFace

I agree but the original post said "times are tough and it's 3.99 a gallon here" batteries would be so expensive that it wouldn't be worth it. If the poster wants american cars then the Chevrolet Volt easily gets at least 40-45mpg on the highway.

The tahoe is worth $10 000 - $15 000 according to autotempest ads in california and a base model Volt is currently for sale in california for under $10 000. Sometimes the best mod, is a car swap.

Less likely to tip over, newer, better MPG, lighter, safer in a crash. Isn't a prius, fits all the criteria Tahoe_Hybrid mentions.

https://www.cars.com/vehicledetail/d...paign=atempest



But the weight of the vehicle and rolling resistance means than 40MPG is pretty much impossible, even if aero drag was zero (obviously impossible), but even if the aero drag was zero, the maximum mpg according to the calculator is 42MPG https://ecomodder.com/forum/tool-aero-rolling-resistance.php?Weight=2500&WeightUnits=kg&CRR=.015 &Cd=0&FrontalArea=20&FrontalAreaUnits=ft^2&FuelWh= 33557&IceEfficiency=.22&DrivetrainEfficiency=.95&P arasiticOverhead=0&rho=1.225&FromToStep=5-200-5
I agree with what you say aerohead about regearing, I am just disagreeing on the practicality in this specific case.

At #25 permalink, the Tahoe, at Cd 0.37, was already achieving 40-mpg at 45-mph, with it's existing aero, mass, and tires.
I don't know what the 'target' velocity is, so I'm asking.
The Tahoe could be looking at Cd 0.10 pulling a 1-wheeled, gap-filled, full-boat-tailed, tadpole trailer, so there's some wiggle room on travel velocity.

[ksa8907]

Originally Posted by AeroMcAeroFace

I agree but the original post said "times are tough and it's 3.99 a gallon here" batteries would be so expensive that it wouldn't be worth it. If the poster wants american cars then the Chevrolet Volt easily gets at least 40-45mpg on the highway.

The tahoe is worth $10 000 - $15 000 according to autotempest ads in california and a base model Volt is currently for sale in california for under $10 000. Sometimes the best mod, is a car swap.

The only reason we kept the hybrid yukon and sold the volt(gen 1) is we needed more than 4 seats. I prefer to drive the volt, way more engaging!

[freebeard]

"a 1-wheeled, gap-filled, full-boat-tailed, tadpole trailer..."



Extra points if it's made from an old VW Beetle body.

[Isaac Zachary]

Originally Posted by ksa8907

The only reason we kept the hybrid yukon and sold the volt(gen 1) is we needed more than 4 seats. Fuel cost is almost irrelevant since I rarely drive any more.

Everyone's circumstances are different. It sounds like the OP wants the Tahoe because he thinks it's safer, not because he needs more space.

My thoughts are that as a fad there's a lot of propaganda to make SUV's seem better than they are, and safety is one of them. Statistically there is no fine line between SUV's and alternatives such as sedans. (Sorry for beating the dead horse a again.)

Personally it makes sense to get a vehicle that meets your needs while avoiding overkill. More than 4 seats could work out in a 5 seat vehicle like a Prius V or Camry or Avalon hybrid. Then there's the Pacifica minivan, which in general a minivan should be more efficient than a large SUV and still haul pretty much the same. But on the other hand sometimes the "perfect vehicle" wouldn't be practical because it costs more to own for other reasons. For an example, I feel that in my situation a newer station wagon would fit my needs the best while still getting the best fuel mileage possible. But alas, the only station wagons available are luxury vehicles, with the exception of a Subaru. Or I'd have to jump into a less aerodynamic CUV or SUV. Sometimes I feel like going mod-crazy and make my Avalon into a station wagon.

[freebeard]

Sometimes I feel like going mod-crazy and make my Avalon Dasher lift-back into a station wagon shooting brake.

[Isaac Zachary]

Originally Posted by freebeard

Sometimes I feel like going mod-crazy and make my Avalon Dasher lift-back into a station wagon shooting brake.

What's a shooting brake?

[rmay635703]

He could do this but would need a way to manually shift and lock up his XMSN

https://ecomodder.com/forum/showthre...mpg-33961.html

[Autobahnschleicher]

Basicly a wagon with a roof that follows the aero template in the rear.

[AeroMcAeroFace]

Originally Posted by aerohead

At #25 permalink, the Tahoe, at Cd 0.37, was already achieving 40-mpg at 45-mph, with it's existing aero, mass, and tires.
I don't know what the 'target' velocity is, so I'm asking.
The Tahoe could be looking at Cd 0.10 pulling a 1-wheeled, gap-filled, full-boat-tailed, tadpole trailer, so there's some wiggle room on travel velocity.

Unfortunately the key word there is could, I agree, that with vast modification and streamlining, full undertray and near full boat tail the Cd could be near to 0.1, but realistically this person is looking for easy mods to get to at least 40-45mpg highway, even if you count 45mph as highway, it is still a tall order aerodynamically to even get to 45mpg without significant rolling resistance decrease.

I may have been pessimistic in my assumption of Crr at 0.015 but even with very LRR tyres (probably not available for a car of that weight) at 0.01 and absolutely no aero drag, 64mpg is all that is achievable.

Everyone's circumstances are different. It sounds like the OP wants the Tahoe because he thinks it's safer, not because he needs more space.

My thoughts are that as a fad there's a lot of propaganda to make SUV's seem better than they are, and safety is one of them. Statistically there is no fine line between SUV's and alternatives such as sedans. (Sorry for beating the dead horse a again.)

Everything is a compromise, very often what you think you need is different to what you actually need.