Poor City Mileage On Ls600Hl

[mcmillmc]

Anyone with experience with poor city mileage on their LS600hL? I just bought a 2008 (only 18,000 miles on it!) and am getting advertised highway mileage (21.9 mpg on a day trip last month) but am getting consistently below 15 mpg city. Advertised is 20 mpg. Anyone have similar experience? Anyone have a solution? Judging from the tach the gas engine seems to be cutting out, at redlights, etc., but I wonder if it's not cutting out enough, or re-starting too early, etc. Thanks in advance.

[James Horning]

When and where last service visit ?

Was the correct oil used during the last service?

Due to the low mileage the, short drives, it is possible there is fuel residue in the oil .

Get the oil and filter changed take the car for a nice long drive get that oil up to operating temp. Use fuel from a well traveled station .

Rolling technology . Enjoy.

[mcmillmc]

Thanks, James. Oil/filter changed 2/4/2013 with 0W-20 synthetic (was synthetic necessary? $60.71 for 9.5 qts.). That was 400 miles ago including a 200+ miles r/t daytrip. This is L.A., I believe the fuel is fresh.

[James Horning]

Perfect! Yes the synthetic is necessary it is the only way you will get 0w20 oil that is specified. This oil among other things is responsible for the fuel mileage. The newer engines are engineered around the oils for mileage ( government) and wear performance. These questions were for peliminary diagnosis only, I have to ask.

Do you know if the valve spring recall applied to your vehicle ? (ALE).

Was it performed?

I have found no service bulletins related to your complaint .

You may just try the old school method of fill tank and calculate , the engine management system does in fact learn the way you drive , give it a tank full and see what happens.

The origional owner completed maybe 3600 miles a year, give it a chance it will come back. Please keep me informed

kenyukai27@gmail.com

[mcmillmc]

Thanks! Yes, got the valve spring recall. Glad to know for sure about the synthetic. I'll try the old school method next tank. (But may take a couple months, as little as I drive.)

[HankJ]

I also have a 2008 LS600hL and consistently get 23+ MPG. I record my milage via Gasbuddies, the on board computer overstates it, in my case. BTW I have 145,000 miles and just bought a used 2010 CPO.

good luck, my likes to be driven.

cheers,

[LS600hL - Papillion]

I just bought a 2008 LS600hL a month ago, and have been getting between 22-23 mpg in mixed city/highway use as a daily driver. I just took it on a trip for the first time, and the trip computer is showing that I've averaged 27 mpg after 300 miles of driving at a constant 77 mph (gotta love that radar cruise control!). Overall, I'm extremely pleased with the fuel economy, and the car itself is incredible in every way so far.

[mcmillmc]

Thanks, Rick. I've had my 600 for 18 mos. now. Get less than 15mpg(!!!). It must be my driving. Putting on less than 2000 miles per year. Just a few miles per week.

But I love it. I worried about battery charging but (so far) it starts immediately, every time. Good luck with yours. What a car.

[Nugget]

I've owned my 2008 LS600H for just over two months now. A beautiful ride. Comfort, power, and economy. I've found with the weather warming over the last couple of weeks the economy has improved noticably, even though I've driven it a little harder than before on motorway runs since. I had 35.8mpg on a 165 mile run, and tend to get 24-25 around town (I'm in UK so slight different calcs may apply for the galon measurement). The electric motor works wonders in slow stop-start motorway gridlock. I've also found that using the cruise control with adaptive off helps. The engine doesn't brake wasting energy already used,and the need to accelerate for the traffic conditions can be controlled far better. Cancel the cruise control early when you see the need to slow down ahead, let it coast instead of braking and charge the battery in the process. And accelerate lightly at low speed to ensure it's battery alone powering the car. I find the V8 kicks in with relatively light acceleration.

[Nugget]

US conversion of my mpg above.

30(US)mgp for my 165 mile road trip.

21(US)mpg around town, although I think I could get much better if I accelerated to a 30mph limit lightly enough to use battery only, but I fear the road rage incidents that I'd encounter taking so long to do so lol.

And my overall average for the last two and a half months (3200 miles) has been 23(US)mpg, which I believe will increase through summer.

The hybrid battery is clearly like me and is happiest in warm weather :)

Sorry if I've bored you with my rambles.

[jainla]

Getting good hybrid mileage really depends on letting the car warm up. For the first 10 or 15 minutes the car's priority is getting the cats and all the other powertrain components up to operating temperature; so the engine runs almost constantly. If you take many short, infrequent city trips (like I do during the week) then you'll be getting about 13-14 mpg. My LS430 over the same route gets about 12 mpg for whatever it's worth.

Once warmed up; out on the open road 25+mpg is possible. I've seen 28-29 mpg on the way to Palm Springs; although this is at speeds well above the legal limit. I'm sure someone who was more afraid of the law could top 30mpg easily.

Usually I find accelerating under battery power to be not that efficient because then you have to run the motor at some point to charge the traction battery. It's actually better to accelerate quickly to about 30/40 mph; then ease off the gas and let the electric motor take over. Coasting gently to a stop and using as much regen braking as possible is the most efficient way to charge the battery. Coming home from the gas station through lightly crowded city streets late at night I saw 37mpg reported this way.

Amazingly efficient car for the power and weight; usually at least 10/20% more efficient than the LS430 over the same route.

[mcmillmc]

Thanks Jainla, that was very helpful. I think I'm doomed, only short trips, 1500 miles per year. Best mileage is 17, usually <15. But I love the car. Interesting comments.

[jainla]

You have to let it ruuuuuun on the freeway with the other cars.

FWIW a 460 or 430 in the same scenario would get even worse mileage; so you're saving the planet a little bit anyway.

Thanks Jainla, that was very helpful. I think I'm doomed, only short trips, 1500 miles per year. Best mileage is 17, usually <15. But I love the car. Interesting comments.