PLW2

I hate to post another question about gas mileage on this board, but after reading several MPG posts, I'm still trying to figure out how to consistently get 35 mpg in the city.

Two months ago I bought a 2011 HS with 23k mi. My first tank of gas averaged around 31 mpg. After reading posts and other tips on hypermiling, I was able to get 35.5 mpg on my next tank, and about 33.5 on my next tank.

Since then, I've been struggling to stay at 30 mpg, with no real difference in driving. My last average was around 27. My Lexus service rep suggested switching to Premium Unleaded fuel and my current tank avg is still only around 29 and I'm driving like an old lady.

I like the car and would recommend it to anyone. The feedback the system provides is great and helps me change my driving habits to get better results. However, my expectations were to get close to the advertised 35 mpg in the city and that doesn't seem to be happening. I don't know why I was able to achieve it once, but I can't get close to it now.

Any suggestions?

Itsjerald

Great question as I just made a post about it as well, not sure your driving conditions but for me as long as I stayed in the green Eco section for the most part of my driving even with the air con on , I am able to get 34-35. Maybe get an oil change ? Possibly can help .

As I am a new owner myself , I look to this forum for great help from the seasoned members .

If you have any idea on how to get the DRL WHITE, without affecting the high beam to work any less than normal , I'd love some input .

Thanks again

rajeev6

TN and CA - both of you should expect to get 36-38 if not 40-42 with a little bit of effort.
I've 2010 HS with around 40k miles and in winter around here in NY it drops down to 30-32. with little bit of help from weather - temps around 70-80F, I can easily get 38-39. As you can imagine, there're several other factors but 30 definitely is low.

TheAirman

City mileage is tough, especially when you have people behind you that want to move fast, and with the A/c on, all bets on mileage are off because the engine runs on for a longer period with the A/c on. I never could figure out why because the A/C compressor is electric.

Maybe try running in ECO Mode. When you come to a light, and the ICE shuts down, go into EV mode. That way you can accelerate up to around 20 harder without the ICE starting. Watch your speed and when you get to around 18, chop the throttle, switch out of EV and reapply the gas watching the hybrid meter and keep the needle in the first green band only. The ICE won't start and you can run it gently up to around 41 on electric only

If you find ICE starting, usually the only way to get to shut down is to run it up to around 38 mph, chop the throttle, it'll shut down, reapply the gas gently in the first green band only and try to hold it to 40 mph.

Watch your mileage climb using the "CURRENT" setting on the display in the middle of the hybrid meter.

And of course, it'll' work different with the A/C on.

Practice.....Practice..... and so on..............

Magellan55

Assuming your driving profile hasn't changed, the warmer weather now, compared to the spring when you bought the car, may have a lot to do with it. Your AC is on more, which uses up a lot of energy. The "sweet spot" for engine efficiency is typically designed for around 60-70 degrees, so as the outside air gets warmer than that your mpg drops.

Some other ideas:
- Are you using the same gas station each time? One brand may have more ethanol content (less energy dense) than another.
- check tire pressures - maybe you have a leak.
- are you driving the same way / same amount each time? Your mpg can vary greatly from EPA if your driving profile differs from theirs. For example, a lot of short trips will kill your mpg, as the engine never gets to operating temp and hence never switches to battery.

Hope you get it figured out - my driving profile is mostly highway / back country roads, so I typically experience highway EPA mpg in my cars.

PLW2

Thanks Airman- your posts on this board are always helpful.

The A/C was heavily used as the temperatures were 95+ during the period that the MPG was significantly decreased. I thought A/C wouldn't affect the mileage too much since it doesn't run off of the hybrid battery and, as you mentioned, the compressor is electric. I understand that severe heat can affect battery performance also. However, all that said, I was shocked to see it go down to 27 mpg without major changes in driving habits.

I took the advice of my Lexus rep and am on my second tank of Premium fuel. I am back to getting 31-33 mpg. I don't know if the fuel selection was the major factor or if the weather cooling off a little helped. However, I would still like to see 37-40 mpg like many others have claimed.

Regarding ECO mode, I always keep it in ECO mode- I assume that is best for gas mileage, but is that incorrect? Also, shouldn't I get better gas mileage in the city than highway with the hybrid? Advertised mpg is 35 city / 34 hwy. I have noticed that the opposite seems true- I was averaging around 31 until I took a 2 hour highway trip and ended up with an avg over 34, which tells me the highway performance was much hgher than 34 to bring the avg up to 34+.

I'll try the tips you mentioned. For the most part, I've been driving very conservative. I'm not going to start "hypermiling", but there is probably still some room for improvement without completely irritating other drivers behind me.

Thanks again.

PLW2

I think you're correct- the temperature seemed to have a noticeable adverse affect on the performance. Sounds like this car was designed for the S.F. area where the temps are always in the 60-70 range- not Memphis where temps range from 30-100.

I'm not using the same gas station, but I may start doing that. My Lexus rep said using ethanol was the best for the car, but there aren't any stations with ethanol near my usual paths. What kind of gas do you use? Premium? Regular? Do you try to use ethanol?

Tire pressures are good, staying in upper 30s. Routes are typically the same- mostly city. However, I thought the HS was supposed to do better in the city (advertised 35 city/34 hwy). However, I have found the opposite to be true.

I'm pretty happy if I can get ~33 mpg. I still don't understand the drastic drop to 27 mpg I had. I'm hoping the Lexus hybrid battery will stand the test of time.

Thanks for the feedback.

JayGoldste

You might be interested in the fuel consumption data reported by HS250h owners at fuelly.com (http://www.fuelly.com/car/lexus/hs250h). The average mpg (US) for 2011 models (n=2) is 32.7 mpg, while the average for 2010s (n=11) is 31.4 mpg (US).

My own car is averaging 30.2 mpg (US) [7.8 L/100km] in 42,300 kms. Taking into account the severe winters here, and the fact that I'm not into hypermiling, I'm satisfied with my car's overall fuel economy.

sublexus

We purchased our 2010 HS250h new. I use a spreadsheet to record the odometer reading and the number of gallons used for each fill-up. We have driven 40,994 miles using 1,084 gallons of regular gas. That gives us an overall average of 37.82 mpg. We mostly use Shell and BP gas. We drive it like any other car we've ever owned. We use the A/C in the summer and the heat in the winter. I usually do the speed limit or keep up with the traffic flow, whichever is faster. We have taken trips to New England, Florida, Missouri and many other distant locations. We still have the original tires on and they have a lot of use left in them. I try to keep our tire pressure at the recommended levels. From reading about the experiences of others, I have to consider us very fortunate as far as fuel economy goes. Regarding the car overall, it has been problem-free. We still love it and are very happy that we bought it. Barring an accident, I don't see it leaving the family anytime soon!

To the OP, I wish I had some advice for helping you improve your fuel economy and I'm sorry that I don't. Something just doesn't seem right.

JayGoldste

Good point. I've found that the fuel consumption shown on my car's computer is consistently about 10% optimistic compared to manual calculation. The consumption data shown at fuelly.com are calculated on the basis of distance travelled and quantity of fuel used, so they are a pretty good indication of the actual fuel efficiency of different makes and models.

Magellan55

Keep in mind that your profile of "city driving" can be vastly different than the EPA's. I'm guessing the HS250 doesn't get 35 mpg in LA or NY rush hour traffic :-) Same with highway - they stick strictly to the speed limit, probably don't speed up/slow down, or consider hilly roads.

Plus, individual driving habit can make a big difference between you and EPA - my wife gets several mpg less than me in multiple cars, driving the same routes and the same speeds. But she tends to keep her foot on the gas until the last second coming up on a red light, and in general drives in what I call a "nervous" way - always changing speeds :-) That wouldn't be the cause of a sudden drop in mpg for the same driver though.

TheAirman

Get off the premium. It doesn't need it, and I don't see how it can help. It's a hybrid, remember? Save the money over regular and buy yourself something nice. Try a tank of regular or two, and see if the mileage really changes.

Second, you really are "hypermiling". You just don't know it yet. Don't worry, at 4 bucks a gallon, it's not a shameful term.

Third, ECO Mode doesn't give you any better gas mileage by reducing the power or output of your engine, all it does is allow more electric throttle pedal movement. That way you can try to keep it in the first green band while running on electric. In PWR mode, you can still do that, it's just hard to do since the throttle moves less distance to output the same power. Hit a bump, the pedal moves, the neddle goes out of the green band, and the engine starts.

Fourth, Consumer Reports just did a great write-up on hybrid mileage claims. Turbos included. Read it. It's great. The bottom line, hybrids are very sensitive to driving style and conditions. "Your mileage my vary". So for me, my highway mileage here in W PA, has never been lower than 37. And my drive to work, and the store and my weekends, with the rolling hills here, the 35 mph average speeds so common, my weekly overall mileage has never been below 40 since I bought it.

Lastly, city mileage can be tough. If you can keep it in EV Mode and never go over 20, you'll kill on mileage. If you can start out in ECO and keep that needle in the first green band and the ICE doesn't start, you can make it to 40 mph and your mileage will double. But as soon as the ICE starts, that's where the HS and it poor software suffers. The new Camry has updated software and it's ICE will shut off, but the HS runs on and on. The only way to get to shut down again is to run it up to 35 to 38 mph, lift the throttle, let it shut down, and re apply gently the needle in the first green band and glide gas free for as long as the battery lasts.

That's your first step into hypermiling and "pulse and glide". Keep trying.

Magellan55

To me, there's basically four elements to getting good mpg:
- conservation of momentum
- speed
- reduction of friction
- hybrid-unique tricks

The first three can be done with any car; the last one is doing pulse-and-glide as above, and other tricks unique to the hybrid setup (those are covered extensively in other threads).

Here's a good article on the first item, which in essence is to stay off the brakes as much as possible (in a hybrid, stay within the regen range of braking, which means light braking far from where you have to stop), keep your momentum through turns, and no aggressive use of the gas pedal: http://www.motortrend.com/features/e...sphalt_jungle/

For the second, the slower you drive, the less wind resistance. Wind resistance is proportional to the square of your speed, so going from 50 mph to 70 mph doubles your wind resistance. The folks claiming 50+ mpg on their HS usually drive 10+ mph under the speed limit too.

The third area is all about making your car cut through the wind and roll over the road as smoothly as possible. Tires can have an impact, especially if they are underinflated. Carrying a ton of junk in your trunk can reduce mpg, and especially bad are things like roof racks. Mud flaps, nose bras, and window visors also hurt. Even opening your windows or sunroof can drag down mpg.

JayGoldste

I was surprised by how much my new hitch-mounted bicycle carrier increased highway fuel consumption: with two bikes on the carrier I noted about a 15% increase in fuel consumption on a drive from Winnipeg to Calgary.