Same with my Nissan. With lower profile tires, the motor spins even higher at 60 than it used to, so I really have to keep it under 65 or I'm spinning 3K rpm all day. But 55-60 is okay with me, and more people should slow down. People don't understand how much fuel they waste pushing their Tahoes and Avalons along at 70+.

 

I don't mine people driving slow in right lane. It drives me crazy when people do that in fast lane. They drive at 65mph in fast lane and don't move away for faster driver - as if they are "perfect" citizen who follows the law and trying to be example to others. I would say #@% you and get the $#$% out, "You are not police!" Even police don't that stuff, it causes more accident.

 

Lately with seeing cops staring at my car every 500 ft, I've been throwing the cruise on at 65 and just sitting in the 2nd or the third lane from the right. Sure I get passed a lot and people expect me to be going faster in the STI, but my gas mileage has jumped a good 2 mpg from when I was cruising at 80 all the time.

Also, with a degree in aerospace engineering, I can tell you why you use less gas going 55 or 60 as opposed to 70. And it has nothing at all to do with how efficient your engine is and everything to do with Aerodynamic drag.

For those of you fluent in mathematics, Drag = -1/2 * density(air) * velocity^2 * Area * Coefficient of Drag.

What does this mean? It means that drag increases at the SQUARE of velocity. So going twice as fast = four times the drag. three times as fast = nine times the drag. How do you counter-act that drag? by the engine putting out more horsepower and using more gas. Unless your car changes shape at different speeds, you're not going to get better gas mileage at a higher speed, it's a phsyical impossibility.

 

I hate old drivers!! Damn coffin dodgers!!!

You must be retarded.......

 

Nonsense! My Sti has no drag and can go eleventy billion miles an hour!

J/k

I tend to drive 65 in the slow lane as well being passed by people in their big SUV's
When people ask why I'm smiling, I say because they'll cry at the pumps
makes me feel better

 

It is just something that I have noticed from driving 7 different cars.... I don't think it is as much about drag as it is about gearing... at 70 I would be in over drive/top gear and the RPM will be in the power band... they won't be high and burning too much gas and they won't be too low and just wasting the gas... somewhere between 2000 and 3500...

 

i drive 65 commuting and am always to the right, after 9pm i do 55 or even 50 at midnight.
speeding doesnt save you time on the freeway, speeding only saves you time when it means catching a string of green or red lights. so yeah i do my speeding from light to light.

anyone notice how stupid people are when they see a red light from a 1/4 mile away? they slam on their brakes at the last minute...i instantly ease on the brakes even a 1/4 mile away, and let the retards trigger the light, then when my open lane turns green, i floor it and wave as i pass them as they are still sitting there lol

I got pulled over for a headlight violation and cop wrote the wrong Vehicle Code...impeading traffic, which is a point on your record, I'm still trying to get my money back from higher insurance rates since the point has been on my record since march and i just found out about it a week ago. stupid cop.

but when youre doing 45 in top gear at 1400 rpms, you cant tell me you get better gas mileage at 70 doing 3300 rpms, that is simply injecting more than twice as much gas into the cylinders, and more drag.

Maybe its cuz your pedo van is shaped like a ***** and cuts thru the wind lol.

 

uh, I would think its about drag v. gearing ( rpm )


agreed. a condom would just add to the drag

 

Perhaps in your car, but MOST modern cars are geared to get max millage at 65-75mph. I know my truck up on 33's with the 4.88's gets 2-3mpg BETTER at 80 than it does at 65.

 

WTF are you talking about

55mph = fifty five miles per hour. That means you cover 55 miles in 60 minutes
65mph = sixty five miles per hour. That means you cover 65 miles in the same 60 minutes. An almost 6% increase in time savings.

so yes, you DO save time, basic math and physics tell us this.

 

Wrong again, once you get up to speed, it takes the same (roughly) amount of fuel to HOLD that speed, than it does 10-15mph slower. The only time you burn fuel harder, is during accelration, so up hills, from stop lights, and such.

Again basic physics here dude:

Objects in motion tend to stay in motion unless acted apon by an aposing force.

In this case drag is the force you have to overcome, however in most modern cars, the drag on the car is < the amount of power required to stay at speed.

 

May be a little off topic, but I had a point on my record cause the court did not specify that there was a fee for traffic school, so the cert did not go through. They fixed it with DMV (really cool court clerks BTW) but my insurance wanted to charge me for readjusting my rates!!

Once I told them to stuff it, and that I would find a new insurance company, they magically readjusted my rate and took my payment in the course of 2 minutes

But ya, slow people suck!!

 

well obviously going to LA, thats when i do 90 and get to San Diego in 6 hours...i was talking about commuting in the bay...weaving thru traffic doing 80 hardly saves any significant time. I've been commuting to SF from Santa Cruz 2 days a week for the past 5 years lol

well that must be why i do 55 to save gas, my subliminal genius mind is just too smart to let me make it fall below 55.

My Miata gets 31mpg doing 55 and 21mpg doing 80...it must be an NA thing. any car thats at 4000 rpms at 80mph is gonna see better results at a lower mph

 

nuf said

-Gio

 

Weaving through traffic and just going faster are two different things...