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

[oil pan 4]

The best full size cars get about 40 to 45mpg and suv usually get half the fuel mileage of cars so it looks like you're already there.
You know what it takes to almost get 40, just have to unrealistically cancel out most of your aerodynamic drag and there you go.

[Isaac Zachary]

Originally Posted by Tahoe_Hybrid

Don't tell me to buy a prius

if I wanted to die in a accident i would have bought a smart car instead...


The speed limits are high in my AREA 45 to 60mph in the surface streets and if you get hit at that speed you're dead.... even if you have 20 air bags

I have seen it happen lots of times

I'm sorry, but I don't believe that ginormous = safe propaganda one bit.

Sure, in a head-on collision you're safer in a heavier vehicle. But looks can be deceptive. A 2021 Ford F-150 starts out at around 4,000lbs, the same as a lot of full sized sedans. Depending on options a Dodge Charger can weigh 500lbs more than an F-150 curb weight. Sure, your Tahoe has a curb weight of around 700 to 1,000lbs more than that. But you could load the Charger with about that much weight if you wanted to.

Besides, weight and size isn't everything. You're more likely to get into a rollover accident in an SUV. That can cause you to become partially ejected from your vehicle right before it crushes you. I saw a guy kill himself this way right in front of me. He didn't even go off the road, just rolled his Jeep right in the middle of the road with no cars coming after hitting a patch of ice and then dry pavement. Roll overs also let things penetrate your vehicle. I had a friend who rolled his SUV and got impaled by a fence post. I don't know about you, but where I live nearly all highways are lined with metal fence posts waiting for SUV and pickup drivers to roll over on top of them. And I know, you're probably thinking that you're such a good driver that you'd never get into a rollover. But roll overs can happen when other cars just slightly bump into yours. Ever see a police car do a pit maneuver on an SUV? It usually ends up in a rollover.

You're also more likely to get killed by your own cargo than in a sedan, unless you have a good cargo net. Years ago this is how the neighbor lady died. She was in a single car accident, reportedly going only 25 mph before the accident, and was killed by her ski equipment coming up front from the back of her SUV. Of course the same principle applies to hatchbacks and station wagons.

You are also more likely to run over other people, including your family members, especially young children. This is because it's harder to see you're surroundings. When driving school bus there was one time a girl decided to rest on the front of the bus. Good thing we have crossover mirrors on school buses. This is also the reason a pickup truck driver ran over the rear of my flatbed trailer at the Home Depot parking lot. You don't stop for what you can't see.

Looking at driver death rates, the 2008 Tahoe is pretty good statistically, with 18 in a million dying in the 2WD model and 10 in a million dying in the 4WD model. Speaking of the Prius, looking at 2010 to 2011 data 16 in a million Prii drivers have died, which is very close to your Tahoe's statistics. Subarus usually have the lowest death rates statistically. Looking at similar years the Subaru Legacy has a 0 in a million death rate.

Personally I met in the middle of heavy weight and nimble hybrid and got a full sized Toyota Avalon hybrid that gets 40-45 mpg on the highway with no modification or special way of driving other than avoiding going over 65mph.

[Vwbeamer]

using this tool
https://ecomodder.com/forum/tool-aer...resistance.php

and these variables-

Vehicle weight: 2812.3 kg / 6200 lbs
Crr: .008
Cd: .35
A: 2.9 m2 / 31 ft2
Fuel energy density (Wh/US gal.): 33557
Engine efficiency: .28
Drivetrain efficiency: .95
Parasitic overhead (Watts): 0
rho: 1.225 kg/m3


I don't think you can consistantly get the MPG you want with aero mods alone.

[Vman455]

Originally Posted by Isaac Zachary

I'm sorry, but I don't believe that ginormous = safe propaganda one bit.

Good, because it's just propaganda. And what the people who espouse this idea fail to recognize is that driving a heavier vehicle increases crash energy for *everyone* involved an accident.

If you want to be safest in the event of a crash (which, first--don't drive unsafely and you will likely be able to avoid one. In 20+ years driving, I have only been involved in two accidents. Both were rear-ends in which the other drivers were at fault), get a car that deforms, not the popular idea of a "strong" car or truck that doesn't. Deformation dissipates energy and increases the time it takes for you to come to a stop inside the vehicle and the vehicle to stop moving, which reduces the magnitude of your acceleration and thus the force that acts on your squishy insides. The same principle underpins the design of airbags.

[Isaac Zachary]

Originally Posted by Vman455

Good, because it's just propaganda. And what the people who espouse this idea fail to recognize is that driving a heavier vehicle increases crash energy for *everyone* involved an accident.

If you want to be safest in the event of a crash (which, first--don't drive unsafely and you will likely be able to avoid one. In 20+ years driving, I have only been involved in two accidents. Both were rear-ends in which the other drivers were at fault), get a car that deforms, not the popular idea of a "strong" car or truck that doesn't. Deformation dissipates energy and increases the time it takes for you to come to a stop inside the vehicle and the vehicle to stop moving, which reduces the magnitude of your acceleration and thus the force that acts on your squishy insides. The same principle underpins the design of airbags.

The thing is there's no one perfect factor that makes a vehicle safer than all the others. Sure, we can point out little pros and cons all day. But in the end there are only these lines that can be drawn in the sand, the older the vehicle generation the less safe it is, and vehicles with extremely low safety equipment (e.g. motorcycles and some super small economy vehicles not normally imported to the USA.) Other than that there's no fine line between sedans, coupes, hatchbacks, station wagons, CUVs, SUVs, pickups, minivans, full sized vans, and other similar vehicles. Just pick a row of vehicle that works for you and then pick the one with them best safety features, ratings and statistics.

If according to the IIHS 18 out of every million Tahoe drivers are killed compared to 0 Subaru Legacy drivers, in which vehicle am I safer? The Tahoe, which is a large SUV, or the Legacy, which is a mid sized wagon?

[Autobahnschleicher]

Can somebody please explain me why you guys are so obsessed with absurdly large and heavy vehicles?
Also 3,99$/gallon is dirt cheap, here we're looking at the equivalent of 6-7$/gallon.
Get a normal car and you will get the fuel economy you desire.

[Autobahnschleicher]

Originally Posted by Vwbeamer

using this tool
https://ecomodder.com/forum/tool-aer...resistance.php

and these variables-

Vehicle weight: 2812.3 kg / 6200 lbs
Crr: .008
Cd: .35
A: 2.9 m2 / 31 ft2
Fuel energy density (Wh/US gal.): 33557
Engine efficiency: .28
Drivetrain efficiency: .95
Parasitic overhead (Watts): 0
rho: 1.225 kg/m3


I don't think you can consistantly get the MPG you want with aero mods alone.

Drivetrain efficiency of 95% is REALY optimistic for a front engine RWD automatic vehicle.
85-90% is more realistic.

With realistic values for drivetrain (0.85) and engine (0.22) efficiency as well as rolling resistance (0.010), I'm looking at about 20 mpg at 60 mph/100 km/h.
If I reduce the CD to 0.25, wich would mean a lot of aerodynamic modifications, we're looking at about 24 mpg.
Only when you're going full Basjoos and drop your CD to 0.17, you're getting close to 30 mpg but that's before factoring in the reduced engine efficiency at low power(17-26 hp).
Gasoiline V8s aren't exactly great at that.

TL/DR
You won't average 40 mpg at 60 mph with that car unless you go to the extremes.

[Frank Lee]

Originally Posted by Autobahnschleicher

Can somebody please explain me why you guys are so obsessed with absurdly large and heavy vehicles?
Also 3,99$/gallon is dirt cheap, here we're looking at the equivalent of 6-7$/gallon.
Get a normal car and you will get the fuel economy you desire.

I think it has to do with low self-esteem.

[Vwbeamer]

I put in the most optimistic numbers. It's a hybrid, so I upped the efficency of engine. It most likely goes into atkinson cycle. Also, my front engine RWD truck is is more efficent than .85. with lock up torque convertors.

TL/DR

Just saying he not getting 45 mpg using the most optmistic numbers. which is what you're saying also.

Originally Posted by Autobahnschleicher

Drivetrain efficiency of 95% is REALY optimistic for a front engine RWD automatic vehicle.
85-90% is more realistic.

With realistic values for drivetrain (0.85) and engine (0.22) efficiency as well as rolling resistance (0.010), I'm looking at about 20 mpg at 60 mph/100 km/h.
If I reduce the CD to 0.25, wich would mean a lot of aerodynamic modifications, we're looking at about 24 mpg.
Only when you're going full Basjoos and drop your CD to 0.17, you're getting close to 30 mpg but that's before factoring in the reduced engine efficiency at low power(17-26 hp).
Gasoiline V8s aren't exactly great at that.

TL/DR
You won't average 40 mpg at 60 mph with that car unless you go to the extremes.

[Vwbeamer]

Originally Posted by Frank Lee

I think it has to do with low self-esteem.

So many people in Georgia riding in full size trucks, often 3/4 and 1 ton, with a 6 inch lift and 35 inch tires. They all look alike. I think most people are followers and desire to have and be like others in the herd. Low self esteem plays into that, because they don't want to try something different, for fear of not being liked.

Another part is gas is cheap.