Geemaan

Dear Lexus 400H friends
Tried to see if anyone have adjusted regen braking to improve battery charging to improve mileage however looks like it is not possible.
Tried to see if gas quality improves mileage and for sure Shell 89 gas really makes a difference
All those fuel system cleaners,, Engine oils. Tyranny fluids didn't improve mileage.

Started a new thread for improving Mileage to see if seeone has used performance tuning chips into the OBD connectors.
Did it improve Lower end torque,, mileage.
not finding much data from seller..

https://www.ebay.com/itm/Fits-2006-2008-Lexus-RX400h-Performance-Tuner-Chip-Power-Tuning-Programmer-/293611880033?mkcid=16&mkevt=1&_trksid=p2349624.m46890.l49286&mkrid=711-127632-2357-0


Is it worth it or we may end blowing the engine or Tranny since it may alter air fuel ratios..

Thanks in advance

nehal51086

I have one installed.
however my experience is a bit skewed, as at the same time i replaced my aged K&N air filter (had been cleaned regularly) with a new K&N filter .

i feel like it got a bit more power and a few more miles, bit i do not have and science to back it up.

I got mine from Chipyourcar.com , i got tbe "upto" 60hp and 5mpg model.... I doubt I got 5mpgs. I think i mentioned the before and after in another post, ill find it.

https://www.clublexus.com/forums/hybrid-technology/652088-getting-19-5mpg-on-my-rx400h-please-help-2.html#post11091172

I see a big price difference in what i paid and what you linked...not sure if more money means better.

Geemaan

Thanks for the details on K&N Filter and the chip.
To Sumup.on Factors

1. City/Highway --- % of City/Highways.
2. Place where you live (temps) Hot and crazy like AZ or Alaska or Moderate Like CA
3. Miles driven per trip --- Less than 6 miles/trip irrespective of City or highway.
4. Driving style drop in mileage -
   1. Lead feet
   2. Aggressive late braking
5. Driving style increase in mileage
   1. Coasting
   2. Coast + Brake ahead of time (Needs a bit of experience for non hybrid users).
6. AC/Heater
   1. We cannot switch off A/c heater
   2. Set it at a decent level like 78 for long drives and not like 72 (Again a personal preference. Honestly Lexus should not be expecting us to turn off ac and drive for their MPG claims).
   3. If possible see if you can open window a tiny weeny bit in hot areas
   4. Use Dash mats to take heat off dash
   5. Use Sun shade / Blocker for front glass
7. Gasoline
   1. Premium Unleaded Gasoline
   2. Top tier gasoline
   3. Ethanol mix
   4. Comparative Mileage for same grade like 87 rr 89 or 91.
      1. Best Mileage
         1. Shell/Chevron/Mobil/Circle K
      2. Better mileage
         1. QT, Sams Club
      3. Poor mileage
         1. Costco

General day to day actions which can be taken by user (Pampering/Splurge is at bottom)

1. Full synthetics 0/30 or 0/40 results or even 5/30 -- better mileage than high mileage oils.
   1. Engine oil changes @5K to ensure that oil is not disintegrating
2. Oil Filter - Quality oil filter like Mobil in 9.50 USD range
3. Change Engine Oil once in 6 months if driving less than 5K miles
4. Check and Change Air filters atleast once in 12 months
5. Air Pressure + 3 PSI and in hot AZ Air pressure + 5PSI
6. Tranny drain and fill once a year.
   1. Transmission
   2. Differential
7. Brake adjustments for all
   1. 4 wheels and
   2. hand brake
8. Radiator/Coolant drain and fill once a year
9. Fuel system cleaner additive/oil change like Chevron/STP/Lucas

Splurge/Pamper

1. K&N Airfilter
2. Fuel system cleaner @ dealerships
3. Performance Chip