On the contrary, the 400 gets better mpg than the 300...

 

u sure about this?????
how could 400 get better mpg than 300???
no way...

 

bigger engine yes, lighter engine YES

2jz is cast iron (i think) and the 1uz/3uz is aluminum. dead weight plays a big difference in the reason the fat/bloated I6 gets similar gas mileage as the much bigger V8. also guys keep in mind these are seriously baby V8's most V8's are/were 5.0L and have been as big as 8.2 L. now if we had a 5.7L V8 (i wish) the difference would be very substantial

lol, its not exactly true....the gs400/gs430 gets very similar mileage but not necessarily better. although for the extra hp i would def get the V8

 

Don't pay him any attention. He is trolling. Common sense will tell you that if you had the 300 and 400 traveling the same distance, doing the same speed, equal conditions, the 400/30 would use more gas or run out of gas quicker. 400/30 users post that there is about a 1-2 mpg difference vs. the 300...but 2 mpgs adds up over a 100 mile trip.

LMBO!! Are you serious?? BTW, you are the same guy that made the statement below and tried to delete your post after people jumped all over you for making a foolish statement. The cherry on the cake is where you had the audacity to tell someone else to research. GS300 entry level??? OMG...epic fail. Dude I don't believe any statement from you after this post.

Originally Posted by repugnante
Infiniti I35 and Acura TL both were in direct competition with the GS300. This is the entry level midsize luxury sedan category. Each had V6 engines with similar amounts of horsepower. They WERE not ARE in the same class. Granted Lexus out sold them both, but they were all in the same class. Research............

 

+ my car looks like a bag of money! Very true statement.

 

My 5.7L Trans Am gets better economy than my GS400. Common sense will tell you different cars have different gearing and power/torque curves. Dummy. Also, how much harder does the 3.0L have to work to pull the car along at the same speed as the 4.0L? IIRC, in closed-loop operation with the TC locked, the car uses the O2 sensors to command AFR, not a fuel table. So if you have less power on tap, I feel like you'd have to run the motor at a greater load, and, using the O2 sensors, the PCM would fuel it accordingly to maintain target AFR.

Above all else, the 4.0L motor is not just a 3.0L with two extra cylinders... There are fundamental design differences between the two. The is no relationship (linear or otherwise) in MPG, power, etc. between the two motors.

If I understood pop culture I might know what you're talking about...

Don't go around being so quick to slam people. They might not have the same ideas as you, but that doesn't instantly make them wrong. We have all been wrong before here, including myself.

 

Well this is from personal experience. I've had a gs300 and gs400. I'm getting about the same mpg, maybe 1-5 miles different depend on how you drive the car. In average city and hwy combine, getting 280-300miles out of full tank. Don't know about gs430.

 

Ummm...what does your old trans am have to do with this subject? I can honestly say that I can care less what your trans am does. I wouldn't be caught driving that! No knock on you personally, I just don't like that brand or style of car...period. The question at hand was that the 400/430 gets better gas mileage than the 300. The example I stated was only to point out OBVIOUS that the 300 would get better gas mileage in the longer run vs. the 400/430. This isn't my opinion, this is pure FACT that anyone with common sense would agree with. Fact based on the mpg numbers that were posted when the car was brand new. Fact that a engine with more HP will use more gas vs. the I6. FACT, FACT, FACT.

Per your example, I guess I could say that my classic 96 Impala SS gets worse mileage vs. a GS400. Something must not be right since they both are V8. Let's stay on track...as far as your "dummy" statement...I will refrain from using this term back with you online. Only chumps, nerds, 5'7" 150lbs e-thugs resort to name calling online...because I highly doubt this would be said to my face (former college LB). This will be my last post on this subject...it's lame to argue online. Comparing two totally different cars just because they both have V8 is silly.

BTW, that is a hip hop song I heard some time back. Actually has a nice beat to it.

 

Lmao at Goku! Guys is their a reason my navi says I'm only averaging 13.x. Mpg? I drive 6 miles to work and the first 1/2 mile is stop and go.. Then the next 5 miles is highway at at 60mph.. The last 1/2 -1/4 before I arrive at work is constant stop and go red lights.... Same way home everyday commute about 12 miles round trip, is this about right?




Btw just found this comparison between a 98 300 vs a 98 400
http://www.fueleconomy.gov/feg/Find....14326&id=14327

 

It has more displacement, one less gear and still gets better economy. I was making the point that displacement is not the only factor in finding what's going to get 'better' fuel economy. I think you missed that fundamental point.

And quite a few people do. How'd you put it? Fact.

It's not that obvious if people have experienced far different results.

Not everyone has agreed with you.

Well now, if we are going by the FuelEconomy.gov website like Flocko posted, yeah there is a 1MPG difference in the combined rating. Not quite the predicted 2MPG from earlier. The good thing about this website is that only a handful of cars are ever tested and you know that old saying 'results may vary'? That is usually the case with cars. If we even did an uncertainty of 1MPG, that'd be enough to put the GS4 ahead of the GS3.

Is it fact? Again, returning to something I have first hand experience with, my Trans Am makes substantially more power than my GS4 and has 1.7L on it. It still gets better fuel economy and only weighs 150lb less. Again, I think you're asserting your opinion as fact my friend. Everyone is going to have different results. There are several people on this forum who have owned both a GS3 and GS4 and experienced better economy with the GS4. Don't go around saying it's so OBVIOUS that what you assumed is SO FACTUAL. It's not always true bub.

Dang, so you're telling me you experienced something different than what was expected?

Good to see you're above name calling. I love when this internet stuff gets real.

^^^^^
Comparing two completely different motors on the basis of displacement is silly.

Is your car allowed to warm up during this drive? It sounds like you're not getting out of warm-up enrichment and your car is adding fuel and staying in open loop to reach operating temps.

LS1 > LT1

 

@kdick no sir it warms up when I'm halfway their.. Very short commute. I just reset it on the Nav when I was halfway home, HUGE difference in readings. 18-21mph average..

 

Well, before I recommend you spending any money, just run a can a Seafoam through it, break up any carbon deposits. Take off your intake and spray some throttle body cleaner in to the throttle body, no need to take it all the way off unless you feel like doing a thorough cleaning. Lastly, spray MAF cleaner through your MAF. A dirty/malfunctioning MAF can cause really bad fuel economy as well as other issues. A lot of the things to increase fuel economy are general 'good health' practices. If you still notice no change in MPG, I'd say its time for new O2 sensors (just front). Which, I hate to say it, but I don't know an easy way to test if your O2 sensors are going bad (maybe someone who does know can chime in), so you might just have to stomach those. Really, the last thing I would suggest is just throwing money at the car, but there are only a few elements that command AFR. The MAF, IAT, and O2 sensors are the main things. When you clean the MAF though you will also be cleaning the IAT, just so you are aware. Knock this stuff out and let me know your results!!!

 

Thank you I really appreciate it!! So I'll take off my k&n intake, spray some throttle body cleaner in their, then spray my maf with maf cleaner, I guess I'll have to search to find the maf, sorry not too tech savy with mechanics, I actually just searched and found the DIY for both thanks!

 

I circled the area and tried to draw an arrow to be clear haha. Just unclip it and carefully remove it from your intake. Spray MAF cleaner through it and let it air dry somewhere where it is free from dust and stuff. While that is drying (Should be fairly quick) spray out your throttle body with throttle body cleaner. If needed, you can poke it open with your finger or the end of a screwdriver and spray it out with it open. It is essential you get NO solid materials past the throttle body.

Once this is all done, your car should have a hard time starting. Usually throttle body cleaner gives my GS a hard time. Just crank it over a few seconds. If you still have trouble, hold your foot to the floor while trying to start it. This puts it in 'flood clear' mode and allow the motor to 'clear' some of the throttle body cleaner. After that, it should fire just fine.

Do you know how to run Seafoam through the top end?

 

So the area that you circled is where my maf is located right? It's kinda plugged into the area that you circled right? Is my throttle body located right in the middle of the engine where the Lexus logo is? Do I take that part of my intake off?