11 mpg!?? (1 Viewer)

[RCsGX]

Strange.

I have a 2008 4Runner V8 4WD - so it's the same drivetrain as your GX.

In 80/20 mixed Secondary/City driving, I consistently get over 19 MPG. Interstate is 20 MPG @ 70 MPH. That's with a 2" front leveling lift, tricked rear airbags for 1/2" rear lift, 1.25" wheel spacers, and OEM size Bridgestone Dueler HP tires (265/60/18).

I'm about to swap all lubricants over to Amsoil. When I did that to my 07 Land Cruiser (also same drivetrain), I got an 8-10% increase across the board in MPGs.

At 11 MPG, I would suspect that you either have a VERY heavy foot, drive in nothing but stop/go traffic with lots of idling, or there's something wrong.

Maybe something is wrong but Ive taken it to Lexus AND Toyota in 2 different states (Texas and Florida) and both can not find anything wrong. And Id assume they would fine something wrong so they can make some money off of me.

The GX is a couple hundred pounds heavier than your 4Runner AND I running larger / heavier tires that you (285/65/18). But even still I should be getting at least 13mpg city stop and go. Most guys w/ stock GXs are getting between 13-15mpg with strictly city driving.

Id like to get 1-2mpg more but like I said it is what it is. And Im not doing ANY highway driving, its ALL city, stop and go and I take it easy on the throttle. Ive done several tanks w/ easy driving / takes offs and several tanks w/ bat out of hell, drive it like I stole it and I always get around 240-250 miles per tank. It makes no sense that I would get the same mileage no matter how I drive it.

I ran Amsoil fluids in my CTS-V and I didnt notice any difference. In my GX Im running Mobil 1 for most of the fluids.

I increased my fuel economy by double digit % by fixing warped rotors and other worn parts, another fun time.

I just had Toyota check my brakes last week and all is ok. I dont have the spec sheet handy but there was plenty of meat left on both the rotors and pads. Who knows why Im getting 11-12mpg. Im at the point now where I dont even care, I just enjoy the GX.

 

[bamachem]

So, you went from 265/65/17 to 285/65/18?

That's a 6.6% difference in distance/speed.

I also see that you keep referring to _________ miles per tank, but never mention how many gallons it took to refill that tank. When you fill up, are you recording the actual number of gallons that it took to refill? I know, silly question to some, but there are people out there who try to calculate fuel efficiency by using the statistical capacity of the tank as listed in the owners manual instead of the actual number of gallons needed to re-fill the tank as displayed by the gas pump.

So, with that said, you math should be:

[(# of miles per tank) / (# of gallons to refill tank)] X 1.066 (correction factor for taller tires)

Example:

[243.2 miles (from ODO) / 18.561 gallons] X 1.066 = ???

[13.10 MPG (uncorrected MPG)] X 1.066 = 13.97 MPG

 

[bamachem]

First off, a few hundred pounds isn't going to impact the overall average MPGs by much at all on two similar vehicles.

According to the EPA data, you should be getting very similar MPGs to my 4Runner. I have also owned a 2000, 2007 and a 2004 Land Cruisers. The 04 & 07 came with the same A750E 5-speed Transmission shared by both the 4Runner and GX470. The 00 LC had the 4-speed A343 transmission. All of these are full-time 4WD V8. The LC is considerably larger and heavier than the GX/4R chassis. The main difference in them is the fact that the 00 LC came with a 4.30:1 axle ratio, while the 2004 and 2007 LC came with 4.10:1. The 4Runner came with 3.73:1 ratio.

The 2000 LC that I had started with stock tires, then went to 285/60/18 (31.5"), then up to 275/70/18 (33"+). I saw a 1MPG loss when going to the 285/60/18's, but didn't see any additional losses going up to the 275/70/18s.

http://www.fueleconomy.gov/feg/Find.do?action=sbs&id=23836&id=20373&id=25053&id=21590

In the 2007 LC, I typically got around 17 highway and 14 in constant stop/go travels. The 2004 LC was about 1 MPG worse because it was the non-VVTi engine with 238HP instead of 260HP. Both of them took Premium 93 Octane fuel to get those numbers, too.

In the 2008 4Runner, I burn 87 Octane. It's the VVTi V8 with 260HP, but it also has taller axle gearing which translates to lower engine RPM for the same sized tire/wheel combinations.

With the three LC's, I had a total of about 5 years of ownership, translating to more than 100k miles of drive time. I never saw MPGs as bad as yours EXCEPT for when I had an O2 sensor going out on the 2000 LC. I had a few tanks that were 10-12 MPG and knew what it was from my experience with similar vintage 4Runners. I swapped both O2 sensors and the MPGs immediately jumped right back up.

Also, I just looked up the Curb Weights of the three (LC vs GX vs 4R). Here's the results:

LC = 5,390 lbs
GX = 4,730 lbs
4R = 4,545 lbs

So, as you can see, the GX and V8 4R are nearly identical in curb weight (185 lbs difference - the weight of a passenger). They should experience similar MPGs under similar circumstances. However, the LC outweighs the GX by 660 lbs. Again, the ONLY time I ever saw MPGs as bad as yours was when there was something wrong with the truck.

Best of luck with your GX, and I hope you find out what's causing the poor fuel efficiency.

 

[bamachem]

Do you have 285/60/18 or 285/65/18? You have listed both of those sizes in different posts.