Getting 19.5MPG on my rx400h :( please help
09-25-12, 04:24 PM
#31
I've heard the same thing and have done it repeatedly in many cars over the course of 12 years. Never a mishap. The charcoal canister is by the tank. As long as your purge solenoid is good you should be golden. If the solenoid was impaired you would get a CEL almost immediately when the ECU runs it's checks once on.
I'll cut back a bit though just in case.
I'll cut back a bit though just in case.
Last edited by MeryLexmas; 09-25-12 at 04:35 PM.
10-08-12, 09:35 AM
#32
We normally get 27 MPG on 93 octane gas in FL. My wife has been in CA for the past 2 months and is now only getting 22 MPG with 91 octane "summer formula" emissions gas. $1 more a gallon compared to FL and less MPG.
11-06-12, 09:33 PM
#34
it could still be your driving style also. if you accelerate quickly you'll always get bad mileage.
... when you're driving. don't hit the gas hard, use it very lightly and try to feather the gas so only the battery is sending energy to the wheels and teh engine icon doesn't appear. . on a flat surface you should be able to do at least 20mph just on battery and thus you are using no gas.
when you are driving on flat road doing between 30-50mph, as you are cruising, try to barely hit the gas where the battery sends power the wheels only and try not to push hard enough to kick the engine in. it's a game you have to play but it makes a huge difference. when a hybrid set the record for mpg, they used a pulse method where the theory is to accelerate as much as possible only using the battery before the engine comes on and coast until you do it again. the theory is on a 50mph road, you'd accelerate to 60, coast back down to 40, and still average 50. and you hopefully never use the gas engine.
when a stop if coming up in the distance, let off the gas as far as possible away from it and coast. .
... when you're driving. don't hit the gas hard, use it very lightly and try to feather the gas so only the battery is sending energy to the wheels and teh engine icon doesn't appear. . on a flat surface you should be able to do at least 20mph just on battery and thus you are using no gas.
when you are driving on flat road doing between 30-50mph, as you are cruising, try to barely hit the gas where the battery sends power the wheels only and try not to push hard enough to kick the engine in. it's a game you have to play but it makes a huge difference. when a hybrid set the record for mpg, they used a pulse method where the theory is to accelerate as much as possible only using the battery before the engine comes on and coast until you do it again. the theory is on a 50mph road, you'd accelerate to 60, coast back down to 40, and still average 50. and you hopefully never use the gas engine.
when a stop if coming up in the distance, let off the gas as far as possible away from it and coast. .
Although my vehicle is not a hybrid I've decided to try this style of driving and it has helped me a great deal. It takes a while to get use to and can be difficult at times because I live in the big city with stop and go traffic. If there's no one behind me and I'm not in a rush to go anywhere I'll do it. If I'm in the Holland or the Lincoln Tunnel (connects NY to NJ) it's a great time to do it, and it becomes a thing of timing while coasting; how close will I get to the car in front of me before I need to use the breaks. Meaning I would rev up, then coast while people in front of me burning gas, leave a big space in front of me, while the person in front using their brakes to slow down, I'm still coasting as my speed is decreasing and if traffic picks up again I can continue to coast til I hit about 25 ~ 30 mph if not I'll apply pressure to the breaks but not as much as if I was giving it gas the entire time.
It's a matter of timing and also judging when the best time to do it. Sometimes you can hold up traffic but if you don't like it, go around me or wait. You can put up your middle finger, but I can also put up my thumb, index, ring and pinky finger too, so what that doesn't bother me.
Especially with this gas shortage currently in NY and NJ waiting hours on line for gas, I try to burn as little as possible.
11-08-12, 07:26 PM
#35
Although my vehicle is not a hybrid I've decided to try this style of driving and it has helped me a great deal. It takes a while to get use to and can be difficult at times because I live in the big city with stop and go traffic. If there's no one behind me and I'm not in a rush to go anywhere I'll do it. If I'm in the Holland or the Lincoln Tunnel (connects NY to NJ) it's a great time to do it, and it becomes a thing of timing while coasting; how close will I get to the car in front of me before I need to use the breaks. Meaning I would rev up, then coast while people in front of me burning gas, leave a big space in front of me, while the person in front using their brakes to slow down, I'm still coasting as my speed is decreasing and if traffic picks up again I can continue to coast til I hit about 25 ~ 30 mph if not I'll apply pressure to the breaks but not as much as if I was giving it gas the entire time.
It's a matter of timing and also judging when the best time to do it. Sometimes you can hold up traffic but if you don't like it, go around me or wait. You can put up your middle finger, but I can also put up my thumb, index, ring and pinky finger too, so what that doesn't bother me.
Especially with this gas shortage currently in NY and NJ waiting hours on line for gas, I try to burn as little as possible.
It's a matter of timing and also judging when the best time to do it. Sometimes you can hold up traffic but if you don't like it, go around me or wait. You can put up your middle finger, but I can also put up my thumb, index, ring and pinky finger too, so what that doesn't bother me.
Especially with this gas shortage currently in NY and NJ waiting hours on line for gas, I try to burn as little as possible.
11-12-12, 10:57 AM
#36
I have an '09 AWD Rx 350 (non hybrid)
I believe driving style has made a big difference to my mpg amongst other general maintenance factors.
When I first got the vehicle, according to the on board screen I was getting anywhere between 7 and 11 mpg. Way below the average 18 mpg this vehicle rated for. I've since then change the air filter and clean the MAF sensor, pulled out fuses to reset the ECU. Which helped in terms of power and response but for gas milage I think lightening up my lead foot.
Now I get around 14 to 16 mpg. Still a bit below, but better than it was before. I do mainly city driving and try to avoid rush hour the best I can but sometimes can't avoid it. There are times I've done highway driving it was about 17 ~ 18 miles before but now it's low to mid 20's.
I recently had my battery change and now trying to keep track of what I'm getting now. Manually and comparing the on board computer.
I looked the other day and was surprised to see 30 mpg. It's still a learning process and timing is key. When I'm not in a rush or distracted by other people in the vehicle it's much easier to do.
I believe driving style has made a big difference to my mpg amongst other general maintenance factors.
When I first got the vehicle, according to the on board screen I was getting anywhere between 7 and 11 mpg. Way below the average 18 mpg this vehicle rated for. I've since then change the air filter and clean the MAF sensor, pulled out fuses to reset the ECU. Which helped in terms of power and response but for gas milage I think lightening up my lead foot.
Now I get around 14 to 16 mpg. Still a bit below, but better than it was before. I do mainly city driving and try to avoid rush hour the best I can but sometimes can't avoid it. There are times I've done highway driving it was about 17 ~ 18 miles before but now it's low to mid 20's.
I recently had my battery change and now trying to keep track of what I'm getting now. Manually and comparing the on board computer.
I looked the other day and was surprised to see 30 mpg. It's still a learning process and timing is key. When I'm not in a rush or distracted by other people in the vehicle it's much easier to do.
11-12-12, 11:09 AM
#37
Driver School Candidate
Join Date: Oct 2012
Location: Arizona
Posts: 11
Likes: 0
Received 0 Likes
on
0 Posts
On our 2006 rx400, (new to us six weeks ago), the mileage on the computer screen shows higher than the actual mileage as shown by how many gallons the fill-up took. I have measured it now several times, and it always shows higher than actual fuel consumption.
The dealer service rep says something to the effect .. . " the computer is not 100% accurate, as it's trying to measure how much gas goes thru the plugs, low speeds, high speeds, and there is too much going on for the computer to be exact all the time. "
GaryB.
The dealer service rep says something to the effect .. . " the computer is not 100% accurate, as it's trying to measure how much gas goes thru the plugs, low speeds, high speeds, and there is too much going on for the computer to be exact all the time. "
GaryB.
01-09-14, 08:49 PM
#39
Driver School Candidate
2008 RX400h AWD
Hi,
Please reply with additional information would be greatly appreciated! This is in relation to the mpg drop on my 2008 RX400h. I used to get 28mpg and now I'm currently getting about 20.2mpg. What is going on? Could it be the cold weather? Where I live, we are getting 30-55 degree days and during the summer it is about 85 degrees. But truly, the change started happening after the IPM recall replacement in September 2013, I noticed a huge drop in my MPG! The MPG isn't as efficient as it was when I first bought it in August 2013. I used to get 25mph-28mph and that is very efficient! I've reached out to the Lexus dealership who replaced the IPM multiple times and they keep reassuring me that it's reading normally and that's how it is supposed to read! You see, I drive my car every day and I know how it runs and it isn't the same anymore after the IPM replacement. I also notice that the gas engine pops in more frequently at a complete stop while waiting at a red light. I also notice that when I'm barely accelerating (less than 10 mph), the engine pops in too. Whereas before, the engine doesn't kick in until I accelerate to about 25mph, it would used to be all silent hybrid engine until it reaches 25mph. I like how my car ran before the IPM recall replacement. I take good care of my car, it gets serviced at the Lexus dealership whenever service is needed. All services are up to date with my car, I just don't know what's going on. Any pointers as to how to get MPH back up and more efficiently and why the MPH has dropped so significantly...would be great! Thank You in advance.
-nlayla
Please reply with additional information would be greatly appreciated! This is in relation to the mpg drop on my 2008 RX400h. I used to get 28mpg and now I'm currently getting about 20.2mpg. What is going on? Could it be the cold weather? Where I live, we are getting 30-55 degree days and during the summer it is about 85 degrees. But truly, the change started happening after the IPM recall replacement in September 2013, I noticed a huge drop in my MPG! The MPG isn't as efficient as it was when I first bought it in August 2013. I used to get 25mph-28mph and that is very efficient! I've reached out to the Lexus dealership who replaced the IPM multiple times and they keep reassuring me that it's reading normally and that's how it is supposed to read! You see, I drive my car every day and I know how it runs and it isn't the same anymore after the IPM replacement. I also notice that the gas engine pops in more frequently at a complete stop while waiting at a red light. I also notice that when I'm barely accelerating (less than 10 mph), the engine pops in too. Whereas before, the engine doesn't kick in until I accelerate to about 25mph, it would used to be all silent hybrid engine until it reaches 25mph. I like how my car ran before the IPM recall replacement. I take good care of my car, it gets serviced at the Lexus dealership whenever service is needed. All services are up to date with my car, I just don't know what's going on. Any pointers as to how to get MPH back up and more efficiently and why the MPH has dropped so significantly...would be great! Thank You in advance.
-nlayla
Last edited by nlayla; 01-10-14 at 05:45 PM.
01-10-14, 07:27 AM
#40
Pole Position
Remember when it is cold the gas engine is turning on more to keep your feet warm...THe only method of heat is through the radiator water in the gas (ice) engine. Maybe lexus should look at electric heat.....hmmmmm. That would explain the loss of mileage and also the winter formulation in gas in California which reduces mpg. one other thing when they did the ipm did they do a ISC reset?
01-10-14, 05:41 PM
#41
Driver School Candidate
Hi Omarus, I am having the same problem. I'm getting 20.3mpg which is a significant drop from my usual 25-28mpg. Perhaps I should try to reset the idle and see if that works. Could you show me how to reset the Idle?
If that doesn't work, then I will definitely see the Lexus dealership which I have scheduled for a "fuel efficiency" test - per Lexus Service Manager via phone. They would take your car to the freeway and drive it so they can compare the mgp.
I'm hoping to have this figured out instead of going to a dealership. I will try to reset it. Please kindly provide instructions as to how to reset the Idle Speed Control. Thanks so much.
If that doesn't work, then I will definitely see the Lexus dealership which I have scheduled for a "fuel efficiency" test - per Lexus Service Manager via phone. They would take your car to the freeway and drive it so they can compare the mgp.
I'm hoping to have this figured out instead of going to a dealership. I will try to reset it. Please kindly provide instructions as to how to reset the Idle Speed Control. Thanks so much.
Last edited by nlayla; 01-13-14 at 08:18 PM.
01-10-14, 08:15 PM
#42
Idle Speed
Hi Omarus, I am having the same problem. I'm getting 20.3mpg which is a significant drop from my usual 25-28mpg. Perhaps I should try to reset the idle and see if that works. Could you show me how to reset the Idle?
If that doesn't work, then I will definitely see the Lexus dealership which I have scheduled for a "fuel efficiency" test - per Lexus Service Manager via phone. They would take your car to the freeway and drive it so they can compare the mgp. The dealership I'm going to is charging me $159 to get it tested.
I'm hoping to have this figured out instead of going to a dealership. I will try to reset it. Please kindly provide instructions as to how to reset the Idle Speed Control. Thanks so much.
If that doesn't work, then I will definitely see the Lexus dealership which I have scheduled for a "fuel efficiency" test - per Lexus Service Manager via phone. They would take your car to the freeway and drive it so they can compare the mgp. The dealership I'm going to is charging me $159 to get it tested.
I'm hoping to have this figured out instead of going to a dealership. I will try to reset it. Please kindly provide instructions as to how to reset the Idle Speed Control. Thanks so much.
01-11-14, 06:31 AM
#43
Rookie
Join Date: Aug 2011
Location: Missouri
Posts: 72
Likes: 0
Received 0 Likes
on
0 Posts
Our 2008 RX400h experiences a drop in mileage in the winter on the order of 2 mpg or so. Here in Missouri, the summer temperatures average in the upper 80's and in the winter in the mid 30's. The best mileage we've seen in is spring or fall where the temperatures are generally mild.
The best average (reported by the trip computer) we've seen is 26 mpg. Generally our long-term average is around 23-24.
Jeff
The best average (reported by the trip computer) we've seen is 26 mpg. Generally our long-term average is around 23-24.
Jeff
01-11-14, 08:35 PM
#44
Tips for better MPG in the RX400h:
- Keep your tire pressure at 38-40 PSI.
- Get low rolling resistance tires (LRR) if you don't have them. The OEM Michelin S8 tires are LRR (Green-X). These will add about 3 MPG to non-LRR tires.
- Turn off the A/C if possible (summer AND winter, in AUTO mode the AC is on by default at any set temp). Go to the climate screen and disable AC, and you can still keep it in AUTO without running the A/C compressor.
- Use the heat sparingly in winter. Having a high set temp will make the engine run longer, especially until the engine is warmed up (157° F and up). The heated seats can compensate for a lower cabin temp.
- Keep it under 42 mph to allow longer gliding on battery only. Feather the gas to keep it around 40 mph. Works great when the speed limit is 35 or 40. I can sometimes get up to 1-2 miles on battery only.
- A highway speed of 50-60 mph will get you MUCH better MPG than 60-80 mph. My experience in summer: 55 mph - 32 mpg, 75 mph - 26 mpg.
- Don't accelerate hard, coast as much as possible, and brake lightly to use regenerative braking instead of the friction brakes.
- Buy a ScanGauge computer so you can see the engine RPM and engine temp, so you can practice keeping it in battery only stealth mode at 0 rpm.
- Make sure to perform the ISC reset any time the 12V battery is disconnected for service or gets low on charge. The effectiveness of this is debatable but it can't hurt.
- Keep your tire pressure at 38-40 PSI.
- Get low rolling resistance tires (LRR) if you don't have them. The OEM Michelin S8 tires are LRR (Green-X). These will add about 3 MPG to non-LRR tires.
- Turn off the A/C if possible (summer AND winter, in AUTO mode the AC is on by default at any set temp). Go to the climate screen and disable AC, and you can still keep it in AUTO without running the A/C compressor.
- Use the heat sparingly in winter. Having a high set temp will make the engine run longer, especially until the engine is warmed up (157° F and up). The heated seats can compensate for a lower cabin temp.
- Keep it under 42 mph to allow longer gliding on battery only. Feather the gas to keep it around 40 mph. Works great when the speed limit is 35 or 40. I can sometimes get up to 1-2 miles on battery only.
- A highway speed of 50-60 mph will get you MUCH better MPG than 60-80 mph. My experience in summer: 55 mph - 32 mpg, 75 mph - 26 mpg.
- Don't accelerate hard, coast as much as possible, and brake lightly to use regenerative braking instead of the friction brakes.
- Buy a ScanGauge computer so you can see the engine RPM and engine temp, so you can practice keeping it in battery only stealth mode at 0 rpm.
- Make sure to perform the ISC reset any time the 12V battery is disconnected for service or gets low on charge. The effectiveness of this is debatable but it can't hurt.
The following users liked this post:
Geemaan (07-09-21)
01-20-14, 09:42 PM
#45
some of you gents get ridiculously efficent mpg.
i normally average 27 and when REALLY being super careful 31mpg.... 541 miles on a tank , thats over 860km... UNBELIEVABLE... bravo.
i normally average 27 and when REALLY being super careful 31mpg.... 541 miles on a tank , thats over 860km... UNBELIEVABLE... bravo.