Has anyone acheived better fuel mileage on the GS450h by:

a) installing one of the aftermarket performance chips; or
b) swapping out the GS450h factory chip for a RX400h chip?

 

To be perfectly blunt neither of these will work. No one-and I mean NO ONE- has been able to successfully alter Toyota's ECUs. A RX400h ECU is in all likelihood quite different from a GS450h one. They use different transmissions, engines, and motors. Even if it did plug in, it would do nothing to improve mileage. You can trust that Lexus/Toyota powertrain engineers have done pretty much everything they can to get mileage and performance out of this powertrain.

The only recommendations I can give you to improve mileage is to slightly increase tire pressure, or at least make sure you're at the factory recommended numbers. Keep in mind that raising pressure too high can hurt the car's handling and degrade tire wear.

Also try and change your driving habits. Here are some examples:

• Dont rush up to a red light. This is simple but often ignored. If you see a red light ahead, simply release the gas and let the car coast to the light. The engine will turn off and your mileage will improve.
• Don't accelerate like a granny--or a dragster either. The engine's sweetspot in terms of efficiency is really in the middle of the power band. If you think about it, acceleration is the least efficient action so shortening that period can help. Use brisk acceleration and then maintain your desired speed. Don't get carried away! Or do, it is more fun after all!
• A more complicated manuver is the Pulse and Glide. This is done during constant speed operation where there's little traffic. This is best done under 45 but can be done on the highway as well. To do this ease off the gas pedal and try to get no arrows on the energy display. This is VERY hard so I just shoot for the middle between regen and power of the power gauge. Coast to a specific speed say 32 on a 35 mph road. Then briskly (~40% thottle) accelerate to say 37 or 40. Then repeat. Just try playing around with it.

I learned most of these tricks over at PriusChat. Their powertrain is quite different from ours but many of the same tricks still apply. Visit them if you are really interested in improving your mileage. Keep in mind, though, that their are limits. This is a heavy and powerful car.

This has some useful tips.

The attachment also has some useful information about warm up stages.

 

lucas is on the money here, cracking a Lexus ECU is like cracking anti-matter

Another trick is finding the best route to/where you are going. For instance for me in Atlanta, if I take 285 to and from downtown, I get 3-4 better MPG than driving on 75 S/N and distance is pretty equal.

 

+1 to what lucasb7 said. the only way to get more performance is if you add aftermarket turbo, supercharger, do an engine swap and/or rebuild the hybrid system. but if you are going to spend that kind of money, you would be better off going with a dedicated sports car instead. or maybe the tesla if you have the money.

http://www.teslamotors.com/

 

Can You please tell something more about tesla or turbo? coz I had idea of tuning engine some how. but couldn't find noting on the web.

 

well if you want a high performance electric vehicle, you buy the tesla (if you can afford it). the specs:

http://www.teslamotors.com/roadster

0-60 mph in 3.7 sec
245 miles on one charge
0 emissions

the tesla is a completely different animal when compared to the GS450h, it's like comparing apples to oranges. tesla is 100% electric car; GS450h is a hybrid gas engine/electric motor car.

as for turbo, no one on CL has installed one yet on a GS450h. but there are posts of a speed shop in japan that has installed one on a regular GS (maybe its a supercharger, i forget).

if you are keen on getting more performance, i suggest you buy the owner's repair manual and have a chat with a reputable speed shop in your area to "talk shop" on what you need to do. obviously you will heading into unknown territory, as no one here has done it before. so you'll need to do alot of research to see if turbo is a feasible option for you or not.

i posted in this forum awhile back - tom's has a hyper supercharger kit for the GS450h. that is another option for you. alternatively, you could also consider NOS. it's less complicated than turbo, and should be fairly straight forward to setup.

 

I can afford tesla but dont see point of buying this crazy car. Coz i f something will happen to it. Only option will be taking back to usa to be repaired... (( Is there any option of improving battery charge on gs?
even i am ready to completely loose trunk...
Also i know that turbo is not suitable with hybrid.


__________________________________________________

2007 Lexus GS 450h (black)

 

i have heard of no option in improving battery charge on GS. but that doesn't mean it doesn't exist. you might need the help of an electrical and/or mechanical engineer who is familiar with how hybrids work, and see how to improve on the hybrid system.

 

The GS 450h has been raced but nothing was added to make the battery more powerful. If anything I wonder can we switch ECU's or something so the 3.5 makes the full 306hp in the IS/GS instead of the detuned 292hp?

 

i never understood why it was detuned..

 

correct me if i'm wrong, but the ECU for the 450h takes into account of the hybrid powertrain, so swapping in a regular GS ECU won't work?


the V6 in the GS450h was detuned for fuel efficiency

 

makes sense...now only if i had bought this car for fuel efficiency...lol