Gville350

iTrader: (10)

Anyone seen the Top Gear episode were they put a Prius vs a BMW 3 series (in-line 6cyl) on a track and had the BMW follow the Prius as the Prius was WOT all around the track. The BMW merely followed the Prius closely around the track, and the end result was the BMW had better fuel mileage because he wasn't at WOT hardly at all.

Lesson being, for different driving styles, one car designed for optimal fuel mileage might not actually give YOU the best fuel mileage. So those of you in an IS250 getting IS350 MPGs, you just might have the wrong car for your driving style. I net 21-22MPGs on a tank (IS350) and I'm constantly on the loud-pedal; LOVE LOVE LOVE how the thing pulls off the line, but after the initial push I'm usually ~5 above the limit watching others pass me and such.

I wonder if with the new, lower rolling resistance tires I'll gain some fuel mileage too! Hmmmmmm.

dcskyline

I drive a 2nd gen IS350. Currently, my average is 26MPG. My commute is mainly 13% city vs 87% highway. I travel 86 miles round trip at 5 days a week with fill-ups at about once per week.

I drive it until I hit "E" on the tank and log all my miles through Fuelly.com. I've been doing this since the first day I bought my car.

I recently installed the f-sport cold air intake and it boosted my MPG by 2. Prior to this, my average was ~24MPG.

You can see more stats at my fuelly profile:
http://www.fuelly.com/car/lexus/is35...skyline/190319

Gville350

iTrader: (10)

^Cool to see that the intake helped with fuel mileage. Most people see the opposite because they love the new, found growl of the motor and cannot keep their foot out of it. LOL!

FSportIS

iTrader: (13)

There are couple other members who notice the mileage gain after installing F Sport intake. I also gained about 1 MPG on my IS250 with the F Sport intake even with high rev everyday single day lol .

Jaytea

iTrader: (1)

Yea LOL now looking at it. It was the conversion to MPG from l/100km and posting it confusion :P

robtwo

How did you get so accurate on the percentage?

FSportIS

iTrader: (13)

Wow, very nice website. You also have one of the IS350 with great mileage. Your commute consists of mostly highway/freeway that can boost up your mileage a lot.

I also used to track both of my car mileage manually on with a calculator and i'm consistently hitting the same one.

By the way, in many of your records, you almost got your car with total empty fuel because our car i believe has 17 gallons and you used up to 16.8 in many instances. Be careful my friend!

dcskyline

i was curious to know if lexus was being honest about their claims, so i decided to find out myself. it's been 5k miles since i last installed the intake and the growl has since disappeared. i'm not sure if this is normal, but just an observation.

i track my miles automatically with fuelly.com and they crank out my driving patterns. prior to this, i used to write my mileage down with a pen and notepad.

thanks. yea, running my car down to "E" is a bad habit but i normally have good judgement on how far i can stretch my full tank so i avoid stalling.

i'm currently exploring other driving habits that would increase my MPG further such as:
- Auto vs +/- mode
- sport vs non sport mode
- AC vs no AC
- open vs closed ventilation

i'll report back with my findings. right now, all my tires are at 45 PSI and only drive in sport shift mode. so far, i've been hitting 28MPG per full tank consistently.

also, one observation i'd like to mention is: i started getting better mileages during the last 5k of my oil vs the first 5k of fresh oil. i run full synthetic and switch out every 10k miles. now, i don't know much about cars so maybe someone more knowledgeable can chime in.

Re3iRtH

You're getting better mileage with sport shift mode on a 350. How long have you experimented with this?
What's your typical shift point?
Please report back; I may have to give it a shot!

marks0008

Someone correct me if i'm wrong but I feel like the driving in sport mode (+/-) shouldn't affect anything, mainly due to it isn't technically shifting but just limiting gears.

keyframe13

It keeps the RPM higher so takes more gas

FSportIS

iTrader: (13)

My speculations as follow:
1. "E" does help assuming your force on the gas pedal is not harder than before. This mode makes the acceleration slower and good for traffic.

2. Auto vs +/- mode. This is too general and can lead to inconsistent results. For example, I can turn in auto mode, drive the **** out of it and drive normal on sport mode hence sport mode would have better fuel mileage. I can do the reverse to achieve the same thing. Also, in both modes, the transmission is still automatic. The comparison should be 1500 RPM vs. 2000 RPM vs. 2500 RPM vs. 3500 RPM vs. 4500 RPM shift point instead. I bet 1000 RPM shift point would give the best mileage due to being a turtle lol.

3. AC vs no AC. No AC will give 1.5-3 better MPG. I have personally tested this.

4. open vs closed ventilation. I would say minimal difference in MPG.

I have tested the following and achieve better MPG assuming no change in driving habit, driving on the same car on similar route.
1. F Sport intake for better engine breathing so more efficient engine equal better MPG. You confirmed this as well.

2. Lighter wheel weight such as the TSW Nurburgring (19-20 pounds each vs. 28-29pounds OEM wheel weight). Total of 36 pounds of reduced unsprung mass will require less rotational force from the engine to move the car and hence better MPG.

3. All season tires with better rolling resistant such as Continental ExtremeContact DWS. Don't go bigger and wider wheel/tires set up which will give worse MPG. Less resistant equal less force required to keep the car momentum. However, handling is not as good as summer tire.

4. Mobil 1 advanced fuel economy full synthetic oil. Yep, I gained better MPG using this oil than any other ones.

5. Driving habit. The MORE COASTING you can do with LESS GAS pedal application and SMOOTHER BRAKE, the HIGHER MPG. This can yield a significant MPG difference.

6. RPM shift point, the lower the RPM, the better fuel economy. I have tested 3500 RPM - full rev vs. smooth 1500-2500 RPM shift point on my IS250 on the 50% city, 50% freeway, I get 16 MPG vs. 24.5 MPG.

7. Lower your car gives better MPG. This lead to better aerodynamics especially when you drive a lot on highway, the car will have less wind resistant so the car can coast in high speed smoother without more gas pedal application and hence better MPG.

8. Less weight, better MPG. Driving with all 5 passengers vs. you alone will yield a difference in MPG.

Your finding about the oil change with last 5k miles giving better MPG is very interesting.

Mike_1GO

iTrader: (2)

higher octane gas = better gas mileage. 89 vs 93 BP. 25.5mpg vs. 29mpg with 93.

Mike_1GO

iTrader: (2)

and conti DWS are NOT LRR tires. The newer conti pure contact with eco plus is an LRR tire.

FSportIS

iTrader: (13)

Yes, you are correct. I did not say "low", i say "better" rolling resistant than the crap OEM summer tires. I chose the DWS because it offers great wet traction, balanced performance on the dry, better rolling resistant than OEM, great tread life, low noise, and comfortable.