On my daily commute over the past few weeks, I've experimented with various speeds. And I have found the optimum speed to cruise! It's 63-64 mph... My drive is quasi-highway driving (the diet-coke of highway driving). I have 5 mi stretches spilit up by traffic lights (4), and then "city" driving at the end. For the most part, I stop about twice during the stretch, if I can't time the lights properly. Anyways, the MPG's are an astounding 29...

Any ?

 

I took a long trip with about 1000 miles on my TL. The stretches where we averaged about 80mph we were getting 31mpg and at times 32. The secret of course is being able to use the cruise control.

 

I find lower the speed, better the mileage.

50MPH gives me 34+MPG (It's kinda too slow)
while 60MPH gives 32MPG
70MPG gives 30MPG

 

You guys going by the MID or doing the math yourself... Hell my 4runner was telling me I was getting 25 MPG on a 100 mile trip at 65. But when I went to fill the tank I got a different result. It is always off by at least 2 miles a gallon.

 

Optimum speed for gas mileage is around 55-60. As speed increases from 0 up to that point, mileage increases. After that, wind resistance cuts into your mileage and it actually decreases (the Law of Diminishing Returns). Actuary's post illustrates this perfectly.

 

My car "feels" best at 70-80MPH. This is not taking gas mileage into consideration, just the way the car feels on the highway.

 

I've found the MID to be pretty accurate with regards to MPG. Of course, unless you do the math yourself you can't tell if it's accurate on yours or not.

 

I agree w/ you

 

Last May, we took my wife's '05 TL (5AT tranny) on a vacation trip. The car had around 2300 miles on it at the time with the factory fill still in the crankcase. I filled up at a station in my town, reset both the 'B' tripometer and the "Computer" settings, then began the drive. Speeds for the first 50 miles averaged 60-62 MPH. For the next 140 miles, we averaged 72 MPH, and for the last 70 miles before our first re-fill, we averaged 75 MPH. On the re-fill, I was careful to select a pump that placed the car at an angle virtually the same as for the initial trip fill. The math showed 31.25 MPG and the MID showed 31 MPG. When you consider rounding, that's right on the money.. the MID is quite accurate when used this way.

 

Oh, and the MID appears to "sample" pretty frequently.. like maybe every 1/4 mile or so.

 

I just finished a tank. I drove (city/highway) 60-65 on the whole tank. I avoided stoplight racing and just took it easy. When the low fuel light came on I had drove 330 miles . When I filled up the car only took 12 1/2 gallons. My drive to work is 16 miles. 11 are highway.

 

Proper use of Cruise control is definitely the key... Nothing is more aggravating than to keep having to pass the same person going up a hill and then having them pass you on level ground over and over again.

Also, nothing is more amusing than seeing a dopey driver, as we both approach a red traffic light, him flying right by me as I slow down. The end result he's at a standstill, having to jam on his brakes, while I cruise on by no brakes depressed with a smile on my face, when the light turns green.

P.S. Mickey3C - I have found the MID rounds up or down to the nearest whole MPG, but it's darn accurate...

 

Of course you realize this varies by vehicle. I can't tell if you're talking just about the TL or about all cars, since you seem to be stating some broad general truth.

I had an RX300 that followed that rule pretty well, but my Beemers have always gotten their best mileage while cruising at 75 or so. Lotta difference in wind resistance (coefficient of drag).

 

Our TL has same cd. as last gen corvette, right?

Car feels great at 100MPH but I find most efficient speed is somewhere around 50-65 or so. From my experience, it's definitely not over 70MPH, probably not over 65MPH. I tried crusing at 50MPH and it seemed to be savign some gas but couldn't really tell difference between 50 and 60.

 

are there any relatioon between RPM AND mpg?

 

Mike_TX - Yes, painting a broad stroke with a big brush...and the range is probably more like 55-65. Specifically for the TL, I don't know and don't really care...I just cruise around 70 to and from work, 80 on a Sunday drive...mileage is decent, but not as good as if I went a little slower, but where's the fun in that?

RJANACONDA - for the most part, yes...the higher the RPM's, the more gas you'll use, so the worse MPG you'll get.

 

good stuff cd thanks

 

I have to agree with others here, if reset properly etc., my TL's MID is near dead on with each of my calculations regarding mileage.

When it comes to speed our Z71/4wd Suburban has quite a spread in mileage though. At 75-80 it averages 17.5 mpg. If you can stand it and drive 60-65ish it will average just under 22.. Not bad for a loaded "family truckster"....

 

I have found 57-63 MPH (cruise set) will yeild mpg results of about 36-37. Of course thats only if you pull out of gas station, set cruise, and coast into the next gas station.

70-80 mph yeilds 30-32.

Fairly significant difference.

I was able to increase my gas mileage from 22.3 MPG to 26.5 mpg by setting cruise at 60 and using throttle sparingly through town. Morning commute is 10 miles hwy, 5 miles city.

 

No. The best mileage is achieved by running with a steady lowest sustainable speed in the highest gear.

 

I've noticed the TL is pretty aerodynamic. I can throw it into neutral and it maintains the same speed for quite a distance

 

Can someone please share their results for an automatic?

6MT, at 6th gear

55MPH = 38MPG
65MPH = 34MPG
75MPH = 31MPG
85MPH = 27MPG
95MPH = 24MPG
105MPH = 21MPG

See thread:
https://acurazine.com/forums/ramblings-12/hahaha-check-out-82207/

 

Also throttle opening is big too. Even you are at 1500RPM and you are flooring it (and using SS to hold gear at 5th) you are losing HUGE amount of gas.

 

I came from an FX35 before my TL. The guys over on their forum discovered that hiway mileage increased by leaving the car in 5th manual (auto) instead of drive. I tended to believe the guys... next time someone trys an MPG check, try 5th... I drive different everyday depending on weather, mood, traffic, etc. etc. so my results are always skewed.

 

6MT, 3rd and 4th gear between 3.5k-6.6k and 5th gear from 4k-4.5k (45-125MPH) for 26 minutes = 13MPG !!!

 

Accurate for a 6MT, but let's face it folks, who's gonna cruise on today's highways at 55-60 MPH? I get around 31 MPG at 65.

Like I've said in earlier threads, the MID MPG indicator is a JOKE as is! Without question one of the few design goofs in this car ... like being the ONLY car on the road having front fender side markers that don't blink with the turn signals. An instantaneous MPG indicator like in the trip computer on the Nav equipped Accord and ALL Beamers would be the intelligent way to do it. That way everyone could adjust their driving habits for maximum mileage. Do I have to tell anyone the importance of this with what's happening with today's gas prices?

 

Darn... I was driving around 105 mph most of the time but now that i see the gas mileage i will probably bring it back to 90 or so.