Jabberwock

Wow - 29.3 - that's great MPG. My long term mileage on the 06 LS has averaged 21.8 mpg in a 50/50% mix of city highway driving. Not bad at all for a big rear wheel drive heavy sedan. On long highway runs I average 27.6 mpg running at 70-75mph. I drive the car smooth as possible, minimal brakes, no tail gating.

L8RSk8R

Just checked mine, after a 274 mile jaunt.. I'd estimate 240 miles of freeway driving = 23.4

fangtl

Best I ever got was 25mpg ish going from BOS to WAS.

Lavrishevo

iTrader: (1)

I can only achieve 28-29 mpg under ideal conditions and with cruise control on and not exceeding 70 mph.

XJSFan

I am just about the same... Actually, how accurate is the car computer?

writes123

For mine with off spec 225/65R16, trip computer said 21.7. At the pump I calculated 21.6.

warminwisc

I checked my old LS it was 4/10 high

Lavrishevo

iTrader: (1)

The computer is very accurate from what I have read.

seve7

my computer is within 2% from calculated with gps and burping the tank to the absolute max fill. you wont believe it, but on monday i was over 31 mpg at the start of a tank for the first 50 miles lol. net it was about a 300ft in elevation drop, but it did have a steep climb, i was on cruise, i wasnt hypermiling, i usually keep the performance switch on, not sure if its true but i think the cams get some more advance at lower rpms for making more torque without have to downshift. if i just cruise to and from the airport its 72 miles round trip 95% highway, i can get over 27 mpg for a whole tank. if i dont leave the city it can dip as low as 16 for a tank, when i first picked up, i got over 580 miles on a tank driving it back then i ran into a 30mph headwind and my mpgs went down to 22mpg at 65mph, p.s. ive never put anything over regular unleaded in it. and in denver regular is only 85 oct.

writes123

My 05 that came with 18" chrome rims is calibrated for the stock 17" size for speed and mileage. I did the comparison using my GPS mileage "trip meter" and the car's trip meter. So the MPG would be slightly off.

seve7

i got my correction factor from calculating my odometer error via gps, and i burp the tank to the top everytime i fill it, it will usually take almost 2-2.1 extra gallons from when it first stops the pump. using this method i was able to find my exact fuel mileage and fuel mileage error during an 1100 mile

BMW7_LS430

I use the alternate method mentioned here

Step 1. Filling the vehicle's gas tank completely and re-setting the trip odometer. Note: Sometimes it's easy to get the main odometer and trip odometer readings confused, especially if the vehicle is new.

Step 2.
When it's time to re-fuel

Filling the tank completely
Writing down the number of gallons it took to fill the tank
Writing down the mileage on the trip odometer
Re-setting the trip odometer
Example: It took 9.5 gallons to completely fill the tank, and the trip odometer reads 335 miles.

Step 3. Dividing the number of miles driven by the number of gallons it took to fill the tank. The result is the vehicle's MPG for that driving period. Example: 335 miles divided by 9.5 gallons equals 35.5 miles per gallon.

C8V6C

I avg about 20-21mpg each fill up (Doing the trip meter method)...probably 80% highway, but doing 80-85mph most of it LOL.

I can't drive 60-65 around here...people drive nuts cutting off, following too close...sometimes it's safer driving a little faster honestly

jayclapp

The safest way to drive is to just drive the average speed of the traffic. The average is easy to see. Average is when you pass just as many cars as those that pass you.

AlexusAnja

Cruise, tailwind, no traffic, no hills = 29mpg. City traffic = 12 mpg.... wow.