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ckwan

The Most Fuel Economy Speed Would Be?

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Although, most of the FS show us more than 30MPG in fuel economy, but what if I wanna get more? Let's say 33MPG, 35MPG? Which rpm should I keep at 5th gear on freeway to get the most economy fuel consumption? And the speed reading in doing this?

Any of you guys have been done with those experiments? If you do, please let me know. Thanks a lot!

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I did a fairly big trip (for me ~200 miles) on the highway and I'm pretty sure I was doing around 70 on cruise control and I averaged over 30 mpg, but less than 35 mpg. I couldn't fill up my tank all the way because my friends just gave me a 20$ for gas. At that time I had an ebay CAI, but everything else was stock. I can get around 27mpg around town if I can keep my foot out of it. I haven't been very successful at tracking my milage..

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Most studies showed the most fuel efficient speed is 55 mph (90 km/h). Above that speed air resistance becomes a factor.

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I averaged over 40 mpg on my trip from minnesota to oregon and back. It was pretty bitchin. We cruised at 65 mph the whole way, and it was January.

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I think most people get better milage than what my car does, for whatever reason. I've found that in the past. 40mpg is insane. My mom has a Prius and she's averaging like 35.6 now over the life of the car. I have no idea what's she's doing wrong. I think it might be a case of the secret lead food/angry driver, though.

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I've found that on the highway, 65mph is the perfect speed for gas mileage / performance. It doesn't downshift while going up hills, yet you're going at a good pace, and when I go at 65mph I get roughly 33mpg. At 70 it drops to like 30 ish?

RPM wise, at 65mph it's at around 2800rpm's, and at 70 it's about 3k.

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Yeah, I feel kinda guilty subjecting my FS to cruising at 80, which is 3.5k in 5th... But for those twisty sections going through cities, I love that 4th gear is right around 4k, which is my powerband with my boltons. There's just no feeling like that.

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I did something funny tonight. My 6 was alerted by fuel lightimg-294686-1-tongue.gif, so I cruise with 55-57mph, rpm at 2200-2300, it's just perfect for cruising, no cars in front of you causing you hit the brake, and the cars from behind go left or right, some even following you(I found out that was a truck trailer with 20ft containerimg-294686-2-biggrin.gif). And when I top off the tank, it gave me 32.5mpg(I was always going 70mph with no cruise control on, just foot controlimg-294686-3-laugh.gif)

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I averaged over 40 mpg on my trip from minnesota to oregon and back. It was pretty bitchin. We cruised at 65 mpg the whole way, and it was January.

woo7, could you tell me what kind of engine oil you are using? And your current car mileage?

My 6 was 140k, with 10w30, I was wondered is the last time I put some 5w30 in or not. Normally I get 30 to 31 mpg. Thanks for sharing~!img-294687-1-smile.gif

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I use valvoline conventional 5W-30, as soon as November rolls around. The only modifications I had on the car was a muffler from an ES, and a delete of the pre-cat to a straight pipe.

Actually, Along the way, in Glendive, MT, the fuel pressure regulator failed, so we negated about 70 miles of the trip from the calculations, as we did not have a properly running engine. It was a 5-speed transmission, which most definitely makes a difference when it comes to mileage.

P.S. I was running stock ES wheels, too. 195/60/15 fuzion hri's

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The best fuel economy is achieved before air resistance becomes a factor (45-55 mph) which is held as stable as possible, in top gear and with properly maintained car especially tires and alignment. Best if done with cruise control for those who have it. This is true for pretty much every car out there.

As far as practical use is concerned I have achieved 36 mpg once when I was forced to drive at 50 mph from the relatively twisty road and other cars. Once I get to 65-75 mph the mileage is 33-34 mpg.

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The best fuel economy is achieved before air resistance becomes a factor (45-55 mph) which is held as stable as possible, in top gear and with properly maintained car especially tires and alignment. Best if done with cruise control for those who have it. This is true for pretty much every car out there.

As far as practical use is concerned I have achieved 36 mpg once when I was forced to drive at 50 mph from the relatively twisty road and other cars. Once I get to 65-75 mph the mileage is 33-34 mpg.

50mph means 2k rpm at 5th gear. hmm, sounds great!

btw, I replaced the dizzy(new cap and rotor), spark plug(used and gap tuned) and spark plug wires(new), and the drive belts too(both new). Now I'm in using of the first tank of fuel. one or two millimeter over 1/2 indicator line, about 230 miles odoed. So I believe the MPG for my car is changed positively.

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A few update:

Topped off the fuel tank on previous sunday, and today the fuel gauge about pointing to the 1/4 line with 333 miles runned. And will be about 36MPG couple days from now when I hit the gas station again. Yay! I love tune ups!img-297730-1-laugh.gif

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wherever wind resistnace doesn't overcome the factor or your cars torque range is gone = good gas mileage.

my car pulls pretty strong at about 3000rpms so if I can do 80 on the PA turnpike to school (about 3 1/2 hours) I can get there on $15 of gas at $2.85 a gallon, from just about an empty tank. so whereever you car provides torque is technically better so long as the rpms aren't that high.

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Ah~! I almost forgot this thread.img-300691-1-laugh.gif

A few updates:

After I replaced the parts listed above, I got 30.15 MPG the next day of my previous post, then came the other five records, they are 29.97, 30.31, 31.38, 30.98 and 31.74 MPGs. I ended up trying all those experiments, and feel 30MPG would be the limit for my 626.img-300691-2-sad.gif (My 98' Accord EX I4 Cpe got 28MPG tho)

Another thinking, is driving on freeway with 50 mph illegal (too slow that might cause collision)?

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I think 45mph is the minimum speed limit in OH.

Yeah, the Bay Bridge which is 50mph. But I always driving in East Bay, so I will facing the 65mph limit. img-300697-1-tongue.gif But it seems that the driver's handbook didn't indicate the minimum speed limit on freeway within CA. I shall go ask a police officer or highway patrol officer for that.img-300697-2-laugh.gif

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I've seen signs on the highway that said the minimum speed was 45 mph. I think the speed limit was 65 on that highway. It probably depends on the road and the state.

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I think so too. I saw minimum speed limit signs on wikipedia only. And in their description section about California, there aren't any minimum speed limit indicated.

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