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Do I have the record?


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  • 3 weeks later...
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Chicago - Port Washington WI - Chicago

 

On the way back, we stopped in Cedarburg WI, then hit the highway and stopped in Chicago. I would show the pictures for the other sectors...but I had too much fun with a 2006 Bimmer 325i in our group to be proud of my fuel mileage.

 

However, for the last 104 miles, at 70 mph on cruise control...

 

30.9 mpg according to the computer.

 

My trip computer reads + 0.7 mpg higher than reality. Conclusion 30 mpg at 70 mph. Not bad.

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I dunno, maybe it's just me, but this kind of "record" is the same as bragging about setting a record for how long you have gone without sex. The hybrid wienes get off on this crapola. I would rather have the record for the best 60' time!!!
Ron
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I dunno, maybe it's just me, but this kind of "record" is the same as bragging about setting a record for how long you have gone without sex. The hybrid wienes get off on this crapola. I would rather have the record for the best 60' time!!!

 

I think the point is just to show what these cars are capable of mileage-wise, not that anyone here drives like a grandma all the time.

 

If I remember correctly, this thread was started when gas had just rocketed up to $3.20-$3.50 for premium, and many of us were spending $40 or $45 or even $50 a tank for the first times in our lives.

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I think the point is just to show what these cars are capable of mileage-wise, not that anyone here drives like a grandma all the time.

 

If I remember correctly, this thread was started when gas had just rocketed up to $3.20-$3.50 for premium, and many of us were spending $40 or $45 or even $50 a tank for the first times in our lives.

Effin word!

 

I started the thread because I was tired of hearing people bitch about mileage. I did it because I happened to notice that I was getting outstanding mileage on a trip to the lake. I wasn't in a hurry either direction, so I had uber-mileage already. 2 more days driving to work and bam ... I (briefly) had a record. ;)

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  • 1 year later...

Well, I re-upped .... 480.2 miles on one tank ...

 

 

http://burnedimage.afraid.org/lgt/gas1.jpg

 

http://burnedimage.afraid.org/lgt/gas2.jpg

 

http://burnedimage.afraid.org/lgt/gas3.jpg

 

Looks like about the same results as boomshnka except I pushed a few more miles and used about the same amount of gas.

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Someone else made a good point a while back. I had discredited 500 as a realistic possibility. Some have noted that the '07+ Spec.B might have a real shot with it's taller tires and taller 6th gear.

 

500 would be an accomplishment.

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try doing a long distance at 77-78mph ... think when i did a roadtrip to colorado... i managed 28-29 avg... thats including some fun spirited driving...

 

congrats on the 31... i mostly drive city so i get happy when i see 22....

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Holy crap! My last tank of 70% highway and the rest town was the highest I have seen since last summer. I got 332 miles and filled up 14.6 gallons, thats only 22.7 mpg on average. I think the best I have EVER hit was like 380 or 390 on a trip home from TDC to NJ at 3 am with cruise control set at 72 for 4 hours.

 

I guess I should get less with a TD0618g and 290 WHP and the auto but wow! Im impressed

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Yeah I'd say you definitely take the cake with 480 miles with a gt. That is outstanding. I have never tried to see how far I could go on a tankful of gas with careful driving, but on a weekly basis of mixed driving to and from work I average 340 miles.
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The only thing I learned in High School(well the only thing I remember it was the 80's) was my automotive shop teacher telling me that internal combustion engines get their bast gas mileage at 3000RPMs. And I'm still pretty sure he's right. I can get around that 31.5MPG@2900-3100RPMS for a while until I hit a hill.
Let's kick this pig!
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The only thing I learned in High School(well the only thing I remember it was the 80's) was my automotive shop teacher telling me that internal combustion engines get their bast gas mileage at 3000RPMs. And I'm still pretty sure he's right. I can get around that 31.5MPG@2900-3100RPMS for a while until I hit a hill.

 

Your teacher was wrong. ;)

 

If I can cruise on level ground, I can hold around 35 mpg at around 40-45 mph in the LGT. Of course, there's no way I could be patient enough to drive something like 13 hours at 45 mph :lol:

 

The other factor is wind resistance. Air pressure is squared by the change in speed of a moving vehicle. Now this is kind of odd to think of, but basically, from 50 mph to 70 mph represents a 40% increase in speed. So the air pressure exerted against the car at 70 mph correlates to 1.4 squared times the pressure exerted against the car at 50 mph. 1.4 squared is 1.96 ... or approximately twice as much air pressure.

 

Well, at lower speeds, air pressure is a pretty minor factor, but once you start hitting that 40-50 mph "wind", you really start to feel the effects (stick your arm out the window at 20, and then at 40, then at 60 ... notice that the effect isn't linear).

 

So just because you build a car with an uber-tall 8th gear which cruises at 95 mph at 3000 rpm doesn't mean it's going to be efficient.

 

And, ultimately, to get the BEST mileage, you would want to take a very small motor and run it at it's maximum power output to attain the best possible mileage (so maybe a 20 hp motor at 4500 rpm at 55 mph???) ... but then you sacrifice any semblance of acceleration. Trade-offs I suppose.

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The engine runs at it's highest efficiency at peak torque. That rpm theoretically gives the best mileage, but other factors such as gearing and the subsequent speed/wind resistance can affect that.
Ron
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Peak power (as in HP) s the mathematical best compromise between torque and rpm. Torque is the level of best efficiency. Been this way forever. Running at peak HP at any gear at any speed will NEVER get better mileage than runing at peak torque.
Ron
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And??? You can do better still by running well below peak torque.

 

Point is that an engine is most efficient at peak horsepower. The problem is that our engines aren't designed to be efficient in our cars. Instead, they are designed to allow us to accelerate with ease and help us get up hills. But if you really wanted to build an efficient car (fuel wise) you'd build a car with a little engine that takes forever and a day to get to 50-55 mph and cruises at there at peak horsepower.

 

The only problem with that is no one would buy it. So, yes, in our cars, running at peak horsepower will not get better mileage, but with a low output engine and a good CVT, you could build a super-mileage vehicle.

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my Corvette runs appox. 1800 rpm at 70mph and gets 25+mpg that is nowhere near peak torque so your saying run it at 120mph and i would get better mileage. :confused: bosco
Stay Stock Stay Happy
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Point is that an engine is most efficient at peak horsepower.

Peak output is achieved at peak horsepower. This has nothing to do with fuel economy... Fuel economy depends on many other things and generally the lower the friction within the engine, the better the fuel economy... which is why Bosco gets similar highway mileage as we do. (lower rpm = less friction)

lol
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