hankd

I thought that somebody might've done a comparison on similar roadtrips and found that they got better mileage at xx mph than at xx mph. I would think that with our 6th gear, the optimum speed would be higher than on most cars. I wish we had an onboard MPG gauge like Caddy's have just to know...

Just curious what you guys think that speed might be...I've got my own ideas, but wanted to hear from ya'll first...

Later

James1

90mph at 2k will get you a pretty good gas mileage and where you're going fast. But probably the optimal is about 65.

Nightclaw

I don't think I've ever sustained 65 long enough to measure fuel mileage at that speed - LOL!! <img src="gr_grin.gif" border="0"> My experience has been that, on a straight highway run (say from San Diego to Las Vegas), my mileage is roughly the same whether I hold 70 MPH or 80 MPH. That's not enough of an RPM/engine load difference to show any significant fuel cost/savings. At most, on my Z28 anyway, the difference is about 2 MPG going from 70 to 80. <img src="gr_stretch.gif" border="0">

hankd

[quote]Originally posted by Nightclaw:
<strong>I don't think I've ever sustained 65 long enough to measure fuel mileage at that speed - LOL!! <img src="gr_grin.gif" border="0"> My experience has been that, on a straight highway run (say from San Diego to Las Vegas), my mileage is roughly the same whether I hold 70 MPH or 80 MPH. That's not enough of an RPM/engine load difference to show any significant fuel cost/savings. At most, on my Z28 anyway, the difference is about 2 MPG going from 70 to 80. <img src="gr_stretch.gif" border="0"> </strong><hr></blockquote>

With 70 or 80 being 2 mpg better?

Viper

iTrader: (6)

I have tracked it ( tho difficult keeping it at one speed <img src="graemlins/gr_devil.gif" border="0" alt="[devil]" /> ) and found in my M6 anything above 63mph caused the mpg to depreciate quickly. Maintaining that speed, I got 32mpg.

hankd

[quote]Originally posted by Viper:
<strong>I have tracked it ( tho difficult keeping it at one speed <img src="graemlins/gr_devil.gif" border="0" alt="[devil]" /> ) and found in my M6 anything above 63mph caused the mpg to depreciate quickly. Maintaining that speed, I got 32mpg.</strong><hr></blockquote>

63 <img src="gr_eek2.gif" border="0"> Don't think I can pull that off! <img src="gr_grin.gif" border="0">

Viper

iTrader: (6)

Trust me, I'm no longer worried about mpg! I drive on the highway in 3rd and 4th.

LS1powerN20

It depends on what gear you have in your car (i.e. 2.73, 3.42, etc.)

Nightclaw

[quote]With 70 or 80 being 2 mpg better? <hr></blockquote>
Generally speaking, 70-75 MPH gives me between 1-2 MPG better mileage than 75-80 MPH. <img src="gr_stretch.gif" border="0">

hankd

[quote]Originally posted by LS1powerN20:
<strong>It depends on what gear you have in your car (i.e. 2.73, 3.42, etc.)</strong><hr></blockquote>

I'm talking about 6 spd with stock 3.42 gearing...

hankd

Anybody else?

buschman

I get about 30mpg in 6th gear rhovering around 68-70mph.

Buschman

hankd

[quote]Originally posted by buschman:
<strong>I get about 30mpg in 6th gear rhovering around 68-70mph.

Buschman</strong><hr></blockquote>

Can you give so more details as to how you did this? Was it during the day? Flat roads? Did you use cruise control or not? Just curious...

buschman

[quote]Originally posted by hankd:
<strong>

Can you give so more details as to how you did this? Was it during the day? Flat roads? Did you use cruise control or not? Just curious...</strong><hr></blockquote>

It was on a relatively flat road. About a four hour drive. It was a summertime trip to the beach. The first and only long trip I've taken this car on so far. I was thoroughly impressed that a V8 could get that kind of millage. I got over 400 miles out of that tank. Most of the trip was on Cruise but when I went through town with stop lights I was in control. I found that the lower your RPMs the better your gas mileage. Just as long as you aren't so low that you don't have enough power to move along without having to lay on the gas pedal. At 68-70 I'm at about 1500-1600 RPM and can handle any hill or flat surface without dumping a bunch of gas.

Buschman

DriveATransAm

i think having the car off netted the best MPG for me. i noticed A4s arent replying much <img src="gr_grin.gif" border="0"> we dont wanna calculate ours, hehe.

Toxic Texan

I get 22-24 mpg per tank. That is city and highway. Plus that is with some street action. As for best speed.... I couldn't tell ya, but the state of Texas thinks it is 55mph. <img src="gr_images/icons/mad.gif" border="0">

hankd

[quote]Originally posted by Blank:
<strong>I get 22-24 mpg per tank. That is city and highway. Plus that is with some street action. As for best speed.... I couldn't tell ya, but the state of Texas thinks it is 55mph. <img src="gr_images/icons/mad.gif" border="0"> </strong><hr></blockquote>

55? Where? Most of the limits around here are 65...which means 75'ish...

Sounds like we're getting similar mileage under similar conditions. I usually get 21-22 during the week, 24 on roadtrips...