I just upgraded my car

[screwballl]

agreed... lets see some pics

[Lead Head]

Originally Posted by dttuner

Don't listen to anyone here... in 3-6 months, anyone with a V8 is going to be crying like a schoolgirl (if they aren't already).

This may be the end of the SUV, HEMI, HUMMER, and any other god-aweful disgrace to the automotive world.... Thank GOD!!!!!



.

Cylinders and displacement has almost nothing to do about mileage, otherwise the 7.3 Liter engine in an F-350 at my dads work wouldn't get 18-20MPG highway.

You can stick a big block V8 in a civic, and it will still get the same mileage as the civic's stock engine. Weight and aerodynamics determine mileage. You won't see SUVs and Pickups disappear, I think that they will go back to the original purposes, SUVs being for people who like to offroad or go camping etc...and trucks will start actually being used for work again

Anyways, back on topic...

[Boy'nBlack]

Was this a lease?

Originally Posted by screwballl

... of course no need to race with it since you will likely lose with that V6...

Turn left and right during the race :D

Originally Posted by Lead Head

Cylinders and displacement has almost nothing to do about mileage, otherwise the 7.3 Liter engine in an F-350 at my dads work wouldn't get 18-20MPG highway.

You can stick a big block V8 in a civic, and it will still get the same mileage as the civic's stock engine. Weight and aerodynamics determine mileage. You won't see SUVs and Pickups disappear, I think that they will go back to the original purposes, SUVs being for people who like to offroad or go camping etc...and trucks will start actually being used for work again

No, it won't. Weight and aerodynamics are a factor on a moving vehicle, of course. but minor.

Put both engines on a stand. One consumes a crap load of gas just idling, the other doesn't. Fuel and air must fill a much larger cylinder, that amount must be compressed in the same cylinder to a point, and then blown up. Size is most of the equation due to volume. You put the same amount of fuel from the little v6 into a monster V8 and you run lean, hot, and WILL burn a hole in the piston.

A 4.11" x 4.18" bore/stroke is a monster next to the 2.95" bore single bore of the Civic. The prior has 8 of these holes to fill while the later has only 4. by shear volume, it uses more fuel (assuming that we must run at the same air/fuel ratio). There's also a matter of power and mass. Power costs power which in turn uses fuel. So does mass in which the bigger parts take more energy to turn...they're not perpetual machines. Did you know a 6-71 blower can cost 180-300HP prior to adding the final HP gains?

Your dad's truck get's 20-25 because the engine has power to tug the huge vehicle around. Put a civic engine in it and it'd have to work it's butt off to even move. You'd have to floor it all the time, which is gas making energy.

Fuel usage is a nature of the beast, not the car the beast is in.

[onebxr]

If my civic only got 20-25 mpg I would take it back!
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[oldman_gamer]

Originally Posted by Boy'nBlack

Was this a lease?Turn left and right during the race :D

Originally Posted by Lead Head

Cylinders and displacement has almost nothing to do about mileage, otherwise the 7.3 Liter engine in an F-350 at my dads work wouldn't get 18-20MPG highway.

You can stick a big block V8 in a civic, and it will still get the same mileage as the civic's stock engine. Weight and aerodynamics determine mileage. You won't see SUVs and Pickups disappear, I think that they will go back to the original purposes, SUVs being for people who like to offroad or go camping etc...and trucks will start actually being used for work again

Anyways, back on topic...

I disagree....a larger engine gets "good" mpg in most cases because it has to work less. I'm not talking under heavy load.I mean normal every day driving.(any vehicle will use more when under load) BUT some do better because of displacement and HP. A Honda Civic pulling a 1ton load will burn more gas than a big F250 will in 1 mile. HP plays a big role as well in the fuel usage role.It takes less work for a large bore to do the same amount of work ,as a small bore,thus, a small bore will work harder,spending more fuel.
Aerodynamics plays the role in the "long" run, at high speed and fuel savings. The Government states as well as the major car companies,that driving 50 - 55 mph consumes the least amount of fuel on ANY vehicle. Going 65 and more,increases fuel consumption a considerable,measurable amount.

[Hitman]

Chumly, Meet LeadHead, he is our resident Google genius. He is a self Googled expert on everything from computers, electronics, engineering, to mechanics. He is even a Google guru on other topics as well, such as finances, law, economics and even the vast medical field. There is not a topic too tough from him to Google. Don’t worry though, none of the information he provides is his own, so he is not responsible for its accuracy.

[Boy'nBlack]

Originally Posted by oldman_gamer

I disagree....a larger engine gets "good" mpg in most cases because it has to work less. HP plays a big role as well in the fuel usage role. It takes less work for a large bore to do the same amount of work ,as a small bore,thus, a small bore will work harder,spending more fuel.

I can agree, to a point. You're right in that they work less. But the rest is an assumption. They work less, because before everything else, they already make more power due to size. The "no replacement for displacement" side of the story.

But this is a given foundation. Put a 25mpg 427 in a civic and it works less. It's still 25MPG. Here we give or take a very small percentage by the amount of mass it must carry around. It might get 27MPG city/ 30MPG HW. Just assuming. But on a stand it's still a 25MPG engine. Here, we'd for sure get back to reality that a 1400cc engine will carry the civic around and at much better mileage and weight. After all, a 427 block itself is as heavy as the front end of a civic. I can't even move around a vortec bare block in the garage. A 427 block needs friends if you really want to pick it. So that added weight brings the milage back down. You didn't just put a larger HP figure in the civic...you put a huge chunk of iron in the front that it must also lug around.

That minces reality with what we're talking about though. An engine has it's designed in nature. All talk must be on a stand or on the dyno to figure this out. You see what an engine does and what it uses. You then use those power figures to the load (what you're putting it in), wheel circumference, axle ratio, tranny ratio. But the engine still has a fuel consumption number at a given load. That's told to us in a dyno run (which is nothing more than a big brake...thus "engine brake" as their really called). If this fat engine is in a civic, it works less than what? The truck. Ok, so it works alright in the truck fully loaded. It works less in the car. Consumption only goes down to a point. If that engine is still the same 450HP engine you saw on the dyno, it still has that consumption. Why? Because it's still producing that same power based on a standardized load.

The HP figures are based on giving the engine load. By rollers, flywheels, or what have you...you know what the engine does with a load. So here we then have no other conclusion than knowing what it does in a 1500lb car, with 28" wheels, with 3.73:1 rear end ratios, and at any throttle position. Let's say WOT. The car is faster, but not working less. It's still 450HP at WOT. And consuming the same amount of gas as half throttle in a 8,500lb truck. The truck is slower. That's the result of working less: What it does to the vehicle and it's movement (as we intend vehicles to do).

So you're dead on up to a certain point. When we get into work, then that's relative and needs a factor. The engine doesn't work less, it just carries less load and thus the car reacts different. And that's because any and all power plants have a designed nature to them. When you over power, there's a strong demand for the fuel source but it's flat. When you under power, the source must spike. In reality, we hope for the smallest and most fitting plant that has a flat line. That then tells that the engine is Efficient.

Enjoying the ride? This is what I do basically. I'm a Gas Turbine tech. Fun work...for dorks like me I guess. If you put a 20,000HP engine on a generator, you know how much electrical watts it can continue to pull. Like the dyno. At 14K(HP)/9K(LP) RPM, it can hold, say, 25MW. Ramp it up and it does not carry more load necessarily. It does not make more power, thus working less. The load is constant (civic) and the engine makes the same HP based on it's nature at that load. It doesn't use more gas.

What's missing is heat rate, speed, curve, fuel quality, etc...it can be simplified to a curve, but how to read them is much more confusing than they appear. It's very common to have a person get a dyno sheet and see they can make 150HP. Where? When? Usable? And where's the vehicle in all this?

I cruise hours on end with a 173HP v-twin, which really has 74HP for me at even brisk highway speeds (6,029RPM). The fuel used here is the same as it does on the stand. By about .4%. 67MPG last fill up, and a chevy V8 in the duck will not get close to that.

Originally Posted by oldman_gamer

Aerodynamics plays the role in the "long" run, at high speed and fuel savings. The Government states as well as the major car companies,that driving 50 - 55 mph consumes the least amount of fuel on ANY vehicle. Going 65 and more,increases fuel consumption a considerable,measurable amount.

That's actually barf. The government states that all cars are shaped the same, have no standards on shape, all axles are the same ratio, and no standards on ratios, all engines are the same, and no standards on size and output, and all transmissions are the same. Also, in their world...everything is a manual. Automatics, my nature, slip. That's the converter. You lose power in the slip to gain comfort of not shifting. Two v6 mustangs identical to the last bolt; yet one fitted with a manual, will be better on the highway at 55MPH. They state this isn't true, because the auto is perfect at 55 as well. It's worse by several digits. It should go 50 to meet the same MPG figures.

The speed limit use to be 75 where I'm from. When it went to 55, mileage per gallon used went up on cars. Why? Because they were geared for 75 to be the cruising speed. That's a 3.27 ring to a 3.50 to equal out. They're then dogging the engine to go slower than the designed cruising speed.

Now take the Liberty, which is as aerodynamic as a spitball, and I get better milage at 70 than I do 55. Why? Not because the government said so, but because that's it's nature. 32" wheels, 3.73 rear, 3.7L at 2.1K and giving a very modest 90hp at that speed. If I slow down to 55, I need a shorter gear to get the same. The CJ7 and it's monster 4.56 ratio does not do it's best mileage at 55mph. It doesn't even get good at 30mph.

We get into something we're studying very hard on bikes. It translates to cars just as much. What we are finding to be true, without a doubt, is that you can't make an aerodynamic bike. There's always a rider on top of it. Mess with the front, you mess with handling and the engine's intake and cooling. Yet it doesn't go faster. The rider is still there, same size, same frontal area. Mess with the back...and the old known comes back. The bike goes faster. It's something we've known for years and it's just coming back to reality. The turbulence is much more relevant than cutting air up front. This is the type of stuff they studied to break the sound barrier (the wiggle just before breaking, and why no jets just have wings anymore...the fuselage is part of the wing). I only bring it up because aerodynamics are far too simplified to be put use as fact. If you follow any racing, you'll see many factory teams struggle with speed. They mess with the engine, they mess with the bodies...but still fight to go forward fast. Watch Honda and Yamaha struggle with awesome engines not make speed. Ducati is still the fast beast.

Seriously, no one knows. It's 10 years of college, doctor types, 30year field guys, all having a wack at it for 50 years. And we get close. Here, it's stated that there's a fact about aerodynamics and that it's for sure that there's a blanket clause on all vehicles at 55MPH. The flaw in that is pointed out. But we do know that if you happen to have a 10lb force on a front, an engine with 100HP, know the size of tires and all that, and what the engine does...you know it's economy.

Parting shot: a Gas turbine is, at worst, 80% efficient. Recip engines are under 30%. Why are we using resources to change the gas used and not...really...the gas consumed? Because we all simply think of power and not the important aspects as in heat rate, actual efficiency, and use. When we think "efficient" today, we think of green...stuff. The engine used is still not efficient, not green, and you just pour something else in it based on fossil fuel. "Efficient" is the effective power output vs. input...NOT gas consumption. Our terms are being misused, and that's why we're in this discussion. As Hitman points out, we all know what we google. We'll debate on it even. Anyone working in this, or have a thought of their own? Not to make it pointed, but you must question what you read. Degree's aren't needed, but a person should have some account of what they're working with to have a side in stuff like this. It's just a bit jaded to have facts given forward which are worth strong questioning.

Wow...I love this place, but I gotta get a grasp of my typing. I'm going to bore the hell out of everyone.

[theburan]

Originally Posted by Boy'nBlack

Was this a lease?Turn left and right during the race :D

But it's a mustang! They aren't made to turn during races! Just kidding, just kidding (the new mustangs do have the solid rear axle, right? I thought they did... hmmmmm).

Back on topic though, pics!!! lol.

On the side topic though... I think Boy'nBlack covered it very well. If there's one thing physics classes have taught so far in class, is that the closer and closer you get to modeling something in the real world accurately (with equations and such), the messier and harder it gets to be accurate. (And it gets messy fast.)

[Hitman]

I have a feeling we are going to be seeing quite a bit more of Chumly over here in the HL.

[onebxr]

Lets look at this from a different angle. I had a Ninja 250 and a Ninja 650, both were parallel twins and both were motorcycles. The baby ninja put out ~25 hp and the 650 put out ~ 80 hp. The baby ninja got ~60 mpg whereas the 650 got ~40 mpg. The 650 didnt weigh more than 100 lbs more than the 250 and the aorodynamics on the 650 were actually better than the 250. And the 650 had FI whereas the 250 was carburated. The 650 was going with 2006 technology as the 250 was going with a designed engine not changed since 1982. So if we go by what some of you were saying, the 650 should get better gas mileage than the 250, I will have to agree with Chums in that the only reason the 650 got worse gas mileage was because of engine displacement and the need for the engine to use more fuel to push the engine and the pistons. Both bikes were ridden basically the same way in fact I probably pushed the 250 further than the 650, due to the fact I was closer to redline with the 250 than with the 650.
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