Replaced Car Battery - horrible mpg
03-08-13, 10:05 AM
#1
Replaced Car Battery - horrible mpg
I had to replace my car battery and it was removed more than 30 minutes thus the ECU has been reset to original setting.
Now my car mileage has gone from 400 miles for full tank to about 325 miles. It's been like 5 gas tank fill-ups since the battery replacement. I thought the RX would have learned my driving habit by now.
What should I be doing to get my mileage per gallon back to its normal 400 miles to one tank?
Now my car mileage has gone from 400 miles for full tank to about 325 miles. It's been like 5 gas tank fill-ups since the battery replacement. I thought the RX would have learned my driving habit by now.
What should I be doing to get my mileage per gallon back to its normal 400 miles to one tank?
03-08-13, 01:51 PM
#2
The DTE value is just an estimate. Were you really getting 400 miles on each tank previous? How were you calculating your MPG previous to the battery change? If you have been relying on just the computer display it was more than likely wrong. Getting 400 miles on a tank of gas is usually what I get when I am doing highway only. Chances are your actual MPG has not changed all that much and that your display value for DTE is a now a bit more accurate.
Calculate your MPG using actual total mileage traveled since list fill up divided by fuel used. See what you get.
Calculate your MPG using actual total mileage traveled since list fill up divided by fuel used. See what you get.
03-08-13, 04:03 PM
#3
the other thing that you should have done since your ECU was reset, was to do a proper startup.
after the battery cables are reinstalled, start the car, and do not touch the throttle. allow the car to run for a few minutes, at least til it reaches normal idle. this lets your computer relearn the base inputs.
doubt this is your problem, but its free, worth a shot.
after the battery cables are reinstalled, start the car, and do not touch the throttle. allow the car to run for a few minutes, at least til it reaches normal idle. this lets your computer relearn the base inputs.
doubt this is your problem, but its free, worth a shot.
03-08-13, 10:44 PM
#4
The DTE value is just an estimate. Were you really getting 400 miles on each tank previous? How were you calculating your MPG previous to the battery change? If you have been relying on just the computer display it was more than likely wrong. Getting 400 miles on a tank of gas is usually what I get when I am doing highway only. Chances are your actual MPG has not changed all that much and that your display value for DTE is a now a bit more accurate.
Calculate your MPG using actual total mileage traveled since list fill up divided by fuel used. See what you get.
Calculate your MPG using actual total mileage traveled since list fill up divided by fuel used. See what you get.
03-08-13, 11:32 PM
#5
Yup, 400 at fill up according to Trip A...I also use Trip B as back up to add all miles together for oil change. I couldn't believe that 400 miles between fill ups was the normal. I do drive like a grandma since I am in my 50's. Lots of highway miles at 65-70mph. (80% of time).
03-11-13, 11:51 AM
#6
400/tank even when fully depleted is very good mpg IMO. 400/19.2 = 20.83 mpg
My car usually gets about 350/Fill (2009 RX350 AWD). I say "fill" because I know that the tank is not empty. Last calculation came out to 330 miles / 16 gal which = 20.63 mpg. So I'd imagine if I ran the gas tank to close to empty, I'd suppose I can get near 400 miles (but I never try to get to empty, always fill at around 1/8). My screen calculation shows 21 mpg which is about right, slightly on high side.
Like suggested, try to calculate real usage by calculating actual miles driven / actual gallons used. They'll give you the clearest indication of what your mpg of your car is, and better indicator of how it's performing compared to your previous numbers or to other similar RX's.
P.s. Gathering from other threads, I think avg for RX350 were 18-22 mpg depending on driving style/conditions.
My car usually gets about 350/Fill (2009 RX350 AWD). I say "fill" because I know that the tank is not empty. Last calculation came out to 330 miles / 16 gal which = 20.63 mpg. So I'd imagine if I ran the gas tank to close to empty, I'd suppose I can get near 400 miles (but I never try to get to empty, always fill at around 1/8). My screen calculation shows 21 mpg which is about right, slightly on high side.
Like suggested, try to calculate real usage by calculating actual miles driven / actual gallons used. They'll give you the clearest indication of what your mpg of your car is, and better indicator of how it's performing compared to your previous numbers or to other similar RX's.
P.s. Gathering from other threads, I think avg for RX350 were 18-22 mpg depending on driving style/conditions.
03-11-13, 12:17 PM
#7
BTW, perhaps you need to reset the ISC as well now.
https://www.clublexus.com/forums/hyb...s-mileage.html
https://www.clublexus.com/forums/hyb...s-mileage.html
Thread
Thread Starter
Forum
Replies
Last Post
amason61
ES - 1st to 4th Gen (1990-2006)
18
10-17-22 07:44 AM
xRYD3Rx
GS - 3rd Gen (2006-2011)
5
05-20-13 03:28 PM
spwolf
Car Chat
18
11-12-10 01:15 PM
