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What speed yields the best MPG?

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What speed yields you the best MPG  

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  1. 1. What speed yields you the best MPG


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planelazy Mentor

planelazy

Posted
Posted
16.1 gallons, IIRC.

 

I've DEFINITELY put 15.7 in mine, which is terrifying.

 

That is scary. I've never gone below 1/4 tank.. I'm anal about that. I don't trust my fuel gauge..

 

My fuel gauge in my semi-truck is about 50 gallons off (200 gallon tanks) so when it reads empty, I get all nice bells and whistles blowing in my face but I know I got about 50 gallons, which gives me about 350 miles.. but I don't rely on it.. the truck's computer measures how much fuel it's used and that's what I rely on.

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Fossil2k2 Proficient

Fossil2k2

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16.1 gallons, IIRC.

 

I've DEFINITELY put 15.7 in mine, which is terrifying.

 

Per the vacation pix its 16.9 US gallons.

 

I've noticed that the "miles renaming on tank" isn't accurate at all. I think the lowest it will read is 40 miles, anything below that it displays "- -". I've taken it past that several times.

 

I think I've seen my fuel light blink before.

 

I've heard some people say that they don't go below 1/2 a tank, they said it reduces wear and tear on the engine. I don't know if I subscribe to that train of thought.

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planelazy Mentor

planelazy

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I've heard some people say that they don't go below 1/2 a tank, they said it reduces wear and tear on the engine. I don't know if I subscribe to that train of thought.

 

You're smart not to buy that junk. Fuel is sucked up from the bottom of the tank, so if the argument was contamination then that person probably has clogged filters (or lack of filters) or some other problem. You can suck your tank dry and still not cause any harm to the engine.. it just won't run. Fuel isn't used to lubricate the motor (only some of the rip off additives are). Now oil on the other hand.. running that low or without will kill your motor

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BigBlack-V Grand Master

BigBlack-V

Posted
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This from an insurance agent...he's my kind of guy.

 

I'm sure rao will say you get the best mpg with the car in the driveway.

 

 

I said it gets the best MPG I never said I drive that fast:)

 

Plus a spec.B cant go that fast unless VTec kicks in yO !!!

I was 0.

 

 

 

And I'm still a zero.

 

:lol:

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Max Capacity Grand Master

Max Capacity

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Yep.

 

You can disagree all you want. But until you sit in a car and watch AVCS action while on CC and off, you can only speculate. Throttle becomes a control function of the system, and the ECU can fuel based on intended throttle position rather than being reactionary.

 

Two identical modern cars, going exactly the same speed, on exactly the same highway side-by-side, and the CC car will get better fuel economy.

 

 

You may have taken my ^ wrong, I agree with you, CC is the way to go.

 

 

As for letting the tank run low, I do it and have done it in all my cars. I normally put in 14-15 gallons.

305,600miles 5/2012 ej257 short block, 8/2011 installed VF52 turbo, @20.8psi, 280whp, 300ftlbs. (SOLD).  CHECK your oil, these cars use it.

 

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Tomkat1127 Collaborator

Tomkat1127

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It seems I average about 22-25 MPG (hand calculated and instant read out). That daily driving consists of intelligent mode in the AM all the way to work (10 miles on streets/back roads at average of about 40MPH) then 30 mile of interstate at an average of 70-75 MPH on CC. Even at that speed I am still getting passed by even a Prius, do you know how bad I just want to stomp on it to beat a stinkin Prius or rusted out Tempo....but nooooo I gotta get that MPG. Then on way home I sometimes run the same expect off the interstate I like to run in S# for the extra oomph for play time, knocking my mileage down by 0.5-1 MPG anyways. Yesterdays' result was about 300 mile travled and it took 12.8 gallon to refill, so that's like 23.4375 MPG (I had been showing off and traveling lots of back roads, Easter weekend).

I think it's hilarious to see the analog gauge max out and the instant read out to say 100 MPG when coasting.

I would love to keep more than 1/2 tank in may car at all times but with the price of gas and as much as I drive, I am usually filling up at 1/8 - 1/4 tank. I am sure it won't kill the pump to run dry once or twice but it makes sense to me that having it in some fuel would have cooling effect on the pump.

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vr4Legacy Experienced

vr4Legacy

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I don't subscribe to the low tank = bad junk theory either. So long as you are regularly driving the car, it's not going to have time settle.

 

Now I don't like to see the light come on because there are 2 stations that are regularly cheaper than the rest. I pass them to and from work, but with the light on I don't feel comfortable stretching for them...

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ehsnils Grand Master

ehsnils

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You may have taken my ^ wrong, I agree with you, CC is the way to go.

 

I would say that keeping a constant throttle at low rpm at high gear will give the best result. CC is not the most economic way to go since it actually does engine braking when going downhill and then add more throttle when going uphill to try to keep a constant speed.

 

But if you allow the car to increase speed downhill and lose speed uphill you will get better economy.

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Max Capacity Grand Master

Max Capacity

Posted
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I would say that keeping a constant throttle at low rpm at high gear will give the best result. CC is not the most economic way to go since it actually does engine braking when going downhill and then add more throttle when going uphill to try to keep a constant speed.

 

But if you allow the car to increase speed downhill and lose speed uphill you will get better economy.

 

 

I did say in previous post that a hilly highway is going to mess with your mpg.

 

I think we all know that a flat highway will give you the best mpg. The area I live in is far from flat. I do use CC every chance I get. I spend most of my 31 mile drive to work on CC. For me I'm convinced that works best.

305,600miles 5/2012 ej257 short block, 8/2011 installed VF52 turbo, @20.8psi, 280whp, 300ftlbs. (SOLD).  CHECK your oil, these cars use it.

 

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Madjik_Man Proficient

Madjik_Man

Posted
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Ditto on the 65-70 range. I have a theory I'd get better mileage off of cruise, but have yet to test it.

 

I always use cruise control and yield much better mpgs

 

On all highway stretches I set the cruise at 68 mph and I can get around 33 mpg

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BAC5.2 Grand Master

BAC5.2

Posted
Posted
My 60mph test today has me at 31mpg after 25 miles.
[URL="http://legacygt.com/forums/showthread.php/proper-flip-key-interesti-159894.html"]Flip Key Development Thread[/URL] "Genius may have its limitations, but stupidity is not thus handicapped." - E. Hubbard
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BAC5.2 Grand Master

BAC5.2

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You may have taken my ^ wrong, I agree with you, CC is the way to go.

 

 

As for letting the tank run low, I do it and have done it in all my cars. I normally put in 14-15 gallons.

 

Nope, I was agreeing with you agreeing with me!

 

CC is the way to go.

[URL="http://legacygt.com/forums/showthread.php/proper-flip-key-interesti-159894.html"]Flip Key Development Thread[/URL] "Genius may have its limitations, but stupidity is not thus handicapped." - E. Hubbard
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Max Capacity Grand Master

Max Capacity

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Nope, I was agreeing with you agreeing with me!

 

CC is the way to go.

 

Glad to see that great minds think alike. Well at least you have proven yourself more then one or two times to be a great mind on this forum. I'm still trying to convince myself that I fit into that category. I have a couple of Engineering buddy's with every high IQ's. But at least I have common sense. :)

 

I have noticed that I get better MPG on my drive back from up in VT on a Sunday night driving south or down to CT. I think it's because most of the drive is down hill. Hence the going south from being up north thing...

 

I have also noticed on my DD if I use CC at 68-70mph, I can get 24-24.6mpg on the dash display over the weeks time.

305,600miles 5/2012 ej257 short block, 8/2011 installed VF52 turbo, @20.8psi, 280whp, 300ftlbs. (SOLD).  CHECK your oil, these cars use it.

 

Engine Build - Click Here

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sactojesse Mentor

sactojesse

Posted
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I thought the 6mt final drive was the same as the 5mt? It was that they had a shorter ratio...

The Spec B 6MT actually has a taller ring & pinion, but lower (numerically higher) ratios in the first 5 gears, so that's probably how you got that impression. From cars101.com:

 

Spec B 6 MT

1st = 3.636

2nd = 2.235

3rd = 1.531

4th = 1.137

5th = 0.891

6th = 0.707

Ring & pinion = 3.454

Drive ratio in top gear = 0.707 x 3.454 = 2.44

 

LGT 5MT

1st = 3.166

2nd = 1.882

3rd = 1.296

4th = 0.972

5th = 0.738

Ring & pinion = 4.111

Drive ratio in top gear = 0.738 x 4.111 = 3.03

 

Thus, 6th gear in a Spec B is quite a bit taller (numerically lower), around 25%, than 5th in a 5MT LGT. I've refrained from using the term "final drive" because in some circles (primarily European) it means ring & pinion ratio, whereas to many Americans it means drive ratio in top gear, i.e., ring & pinion x top gear ratio.

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Max Capacity Grand Master

Max Capacity

Posted
Posted
I sure hope not! I put in 16.2 gallons one time (assuming the pump was reading correctly)

 

I thought the manual said 16.5 gallons is what the tank holds. But I could be wrong....;)

 

Just found this.

 

Fuel tank 2 (US gal, Imp gal) 64 (16.9, 14.1) in the service manual. Page 9 of 6057.

305,600miles 5/2012 ej257 short block, 8/2011 installed VF52 turbo, @20.8psi, 280whp, 300ftlbs. (SOLD).  CHECK your oil, these cars use it.

 

Engine Build - Click Here

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09_Red_GT Rising Star

09_Red_GT

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Posted

Driven on "--" for about 20 miles or so, and then put 16.4 gallons in the tank. It does go down to 10 miles remaining, but that can dissapear and re-appear without notice.

 

And I have no idea how any of you get above 20MPG in this car... I average like 17mpg.

habitual derail-er
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bmx045 Grand Master

bmx045

Posted
Posted
Driven on "--" for about 20 miles or so, and then put 16.4 gallons in the tank. It does go down to 10 miles remaining, but that can dissapear and re-appear without notice.

 

And I have no idea how any of you get above 20MPG in this car... I average like 17mpg.

 

 

yeah well you drive like batman in stop and go traffic...

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BigBlack-V Grand Master

BigBlack-V

Posted
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Driven on "--" for about 20 miles or so, and then put 16.4 gallons in the tank. It does go down to 10 miles remaining, but that can dissapear and re-appear without notice.

 

And I have no idea how any of you get above 20MPG in this car... I average like 17mpg.

 

 

I get = winter 17-19MPG, summer 22-24MPG

 

you prob get only 17mpg because your a masshole and they are crazy drivers:lol:;) jk

I was 0.

 

 

 

And I'm still a zero.

 

:lol:

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