ziggyziggy

so my car is around 750 miles now and i still average around 20 mpg consistently. i had an all-highway 300 mile round trip road trip a few weeks ago and i averaged 25 mpg which is the best i have gotten since buying the car a month ago. but at the time my tires are pretty flat with only 28psi cold. since then i pumped up to 34psi and i still see the same mpg numbers. i reset my trip meter everytime i fill up and as if now it is 1/4 full and about 200 miles on the trip meter. the computer has an average of about 20mpg and 18.9 average since refueling.

now i mostly drive local in brooklyn with temperatures in the 20s recently but still... i notice that when i usually start from a red light, i see the power as coming from the gas engine. after a little bit, if i release the gas pedal and step on it again, power then comes from both the gas and electric motor. i dont see power coming from just the electric motor unless i drive on a long stretch of road where i have already accelerated up to about 25mph and then release the gas pedal and then put my foot back on gently.

but i think the killer is that everytime i start from a red light, i see pure gas power at least up to a good speed but then by that time, i would have hit another red light and need to stop. i thought hybrids are designed for this kind of scenario? if everytime i start up with gas, when is the electric motor used? i always thought that pure electric power is used at startup and gas only kicks in when high speeds are required? i have never seen pure electric mode from stand still. its either pure gas or gas-electric combo. anyone with me here?

Joeb427

iTrader: (1)

My Camry hybrid was at 36-37 MPG average and it's down to 33.3 and may drop lower.
Cold weather,winter grade gas and warm ups kill mileage for me.
MPGs are down with my RX 350 too for the same reasons.

oldcajun

In cold weather, the ICE runs to provide heat to the cabin. It will also run more in cold weather to heat up the catalytic converter. Winter time and low mileage on your car are the likely reasons for low mileage right now.
Steve

JimH2

Having you tried using the "ECO" mode setting for your in-town driving to see if any difference.

sleepysurf

I'm beginning to think we'll see a TSB down the road for this issue. It appears that at least some of our RX 450h ICE's are kicking in immediately even when they theoretically shouldn't (e.g. in warm FL weather), whether in ECO mode or not. I'm beginning to think there's a software or hardware glitch in mine (?? similar to the recent overheating Prius' recall), causing a drop in mpg efficiency. My dealer insists mine is running fine, but it never stays in elec mode, no matter how slowly I accelerate. After 6000 mi, I'm ranging from 24.5 - 28 mpg (mainly city driving).

ziggyziggy

sorry, is this a fact or a guess?? my trips are usually less than 15 mins around town.

ziggyziggy

yes, same results

ziggyziggy

yes, it seems that upon startup from a full stop the ICE always kicks in and i hear a rumble from engine bay. the electric motor doesnt even seem to kick in until i step on gas from coasting. even with light foot on gas, same results.

Jellopy

If you only had about 15 mins for a trip, I think that's why your MPG was so low.
I own 2 hybrids the prius and 450h. I does the same thing in winter.
In first 10-15 mins marks(the engine run cold) the MPG was terribly low like
18-22 MPG for 450h or 28-32 for the prius and it's get better after that.
If someone travel around 30-60 mins per trip they obviously get better MPG than you.

I live in Salt lake city, Freezing cold here. My 450h MPG was like low 20s.
I think every car hybrid and non-hybrid are suffer from the cold the same way.

RXSF

well you answered your own question

when you drive 15 minute trips, you arent even giving your engine enough time to warm up. I notice that I can drive a good 10 minutes before I see the needle of the engine temp up to where it should be since it is constantly being turned off at stop lights and when coasting. The ICE will always want to be at optimal temperature and will want to stay on as long as possible until it reaches that temperature. After that, it will begin to rely more on the electric motors.

according to my avg right now, its at 26.8. After a nights rest, and driving along, it usually drops down to the 25s and then as I continue on my way, it goes back up to 26.

oldcajun

Fact. Where did you think the heat for the cabin came from? The warm up for the catalytic converter is required to meet EPA regs.
Steve

ziggyziggy

For you its 25 at worst, for me its 20, a big difference.

ziggyziggy

Thanks, got it but how much do u average on cold days?

wyau01

Very low mileage this last week. Especially during traffic, you motor stops when you are not moving, so it will take a long time to warm up.

This version is much better than my old '06 RXh, which never gets warm in cold days.

SLegacy99

I'm not surprised. I agree with the others here in that the very cold weather will significantly impact your fuel economy. Not to mention, a cold battery does not operate as efficiently.

However, here is what I really think. 750 miles is not very many. Just like any car it has to be broken in. Our 400h posted around 24 MPG (in warm weather) until it reached 4000 miles. Now it averages anywhere from 25 to 31 MPG.

Of course driving style is also a factor, I don't have to tell you this. We take our 400h from Pennsylvania to South Carolina several times a year. I've found that my dad will average 25 MPG, I do about 26, and my mom will do 28. Everybody drives differently.