Fuel discussions/questions - Octane Regular or Premium (merged threads)
#316
Driver School Candidate
Just got an used 2015 with about 45,000 miles on it. Previously, I had an Infiniti G35 Coupe that was getting 20-21 MPG mixed city/highway driving on that 3.5L V6.
Now switching over to the this 4.6L V8 GX, I'm getting about 18 MPG in mostly city (some highway) driving. Last two tanks on the GX got me about 335 miles with about 20-25 miles of range remaining.
I have to agree with the driving style notion... I coast to lights and stop signs for sure. Definitely not lead-footing it at the line helps a great deal too. Might be slightly annoying to those behind... but I just kind of let them pass me when they can't take it no more. ^_^
Now switching over to the this 4.6L V8 GX, I'm getting about 18 MPG in mostly city (some highway) driving. Last two tanks on the GX got me about 335 miles with about 20-25 miles of range remaining.
I have to agree with the driving style notion... I coast to lights and stop signs for sure. Definitely not lead-footing it at the line helps a great deal too. Might be slightly annoying to those behind... but I just kind of let them pass me when they can't take it no more. ^_^
#317
No offense but 8-9 mpg mixed city and highway doesn't sound right. You should have them check your car.
#318
Racer
If you get 290 miles per tank then you average about 14-14.5 mpg not 8-9mpg.
#319
Lexus Fanatic
first off, I knew going in mpg would not be great however I'm currently averaging 13.8mpg. Car currently has 400 miles on it. Will this improve after the car learns my
driving style and breaks in? I don't romp on it, normal mix or city and highway driving
Reason i ask is I was expecting at least 17-18mpg average.
driving style and breaks in? I don't romp on it, normal mix or city and highway driving
Reason i ask is I was expecting at least 17-18mpg average.
#320
#321
Driver School Candidate
#323
City only 13MPG ..can push it to 15 on a light foot. But my office is only 7 miles away. Lot of signals and stop signs.
Highway driving: Anything above 75MPH I get 18 - 20MPG. Below that, on a light foot and keeping it above 65 its about 22 MPG.
No change post the 10k service in MPG, the engine does rev more freely though.
Highway driving: Anything above 75MPH I get 18 - 20MPG. Below that, on a light foot and keeping it above 65 its about 22 MPG.
No change post the 10k service in MPG, the engine does rev more freely though.
#324
Super Moderator
I'm seeing some interesting city numbers (not enough time on Hwy yet in that mode) with Pedal Commander on ECO -4.... I need more time but seemingly noticeably improvement.
#325
Driver School Candidate
Let me shine light on this if you will. Most areas of the us now have 10% ethanol in the gas. Ethanol is 113 octane fuel. Adding 10 % ethanol makes 87 octane fuel more like 90 octane all in. If you also factor altitude into the equation (I for instance in Missouri at approx 1500 feet) 90 octane is equivalent to 92 at sea level. Lexus recommends higher octane out of caution for the area of the world the car is and what fuel is available. Ethanol is not common in most areas of the world. Also burning octane higher than needed for the compression and altitude of the engine will lower the mpg overall with the exception of a forced induction engine.
Run your 87 unless you are running at sea level without ethanol.
Run your 87 unless you are running at sea level without ethanol.
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Tessie (01-08-19)
#326
Driver School Candidate
Great information, Camdog. I fact-checked you (please don't take offense!).
87 octane fuel + 10% ethanol = 89-90 octane fuel
This website validates your information:
https://mnbiofuels.org/media-mba/blo...-for-beginners
You are correct, sir!
87 octane fuel + 10% ethanol = 89-90 octane fuel
This website validates your information:
https://mnbiofuels.org/media-mba/blo...-for-beginners
You are correct, sir!
#327
Certainly, the computers in these trucks are capable of retarding the timing enough to allow the engine to run reliably. However, I was schooled long ago that running retarded timing over a period of time will almost certainly cause combustion deposits. Has this somehow been solved? Why skimp on fuel whilst driving around in a luxury vehicle equipped with an excellent V8 engine that is likely to be replaced by silly V6's with turbos at some point? Put another way, you are driving a truck destined to be a true classic; so why mess with the engine like that?
#328
Driver School Candidate
RoadDawg I think you missed my point. The vehicle should not have to make any adjustments for the lack of octane in the gas given the ethanol. Also if you are at altitude at all the air intake isn't dense enough to need the higher octane.
Just a side note but the idea of the computer simply is retarding the timing is way to simplistic. This engine has dual overhead cams and VVT so at any nanosecond it is adjusting for numerous differences in air density, fuel pressure, etc etc etc. This is why todays engines last so long and burn so clean. The idea that you can put premium fuel in the engine and the will allow it to run without adjustments is just not so. Everytime you fill up even if it is at the same gas station that fuel will burn differently and is mixed differently. The computer can adjust for this. Fuel is only half the equation also. Air is the other component and every day is different. Cold air is more dense than hot air and on and on.
Just a side note but the idea of the computer simply is retarding the timing is way to simplistic. This engine has dual overhead cams and VVT so at any nanosecond it is adjusting for numerous differences in air density, fuel pressure, etc etc etc. This is why todays engines last so long and burn so clean. The idea that you can put premium fuel in the engine and the will allow it to run without adjustments is just not so. Everytime you fill up even if it is at the same gas station that fuel will burn differently and is mixed differently. The computer can adjust for this. Fuel is only half the equation also. Air is the other component and every day is different. Cold air is more dense than hot air and on and on.
#329
Driver School Candidate
I have put about 17k miles on my 2010 since purchasing in April '18 and used regular fuel for most of those miles with no issues. Recently I started using premium again and my mpg is up, the car feels smoother, and I think the car is making a little bit more power. To that last point, it is pretty anecdotal but while on cruise control I find the car downshifting less which I attribute to a slight increase in power. Fuel is so cheap right now that I see no reason to return to using regular fuel.
#330