MPG of a V8.. I know...

[ElDuck]

Alright. Loving my 07 T4R Limited with the V8. The MPG is terrible. I drive 70 miles a day for work, 65miles of it being mostly flat highway @ 75mph. I was hand calculating my average at 13-14.5mpg. 105k miles.

Specs:
-Stock size, basic Goodyear Assurance A/T's @32psi
-105k miles.
-No lift

Replaced/new/added with no changes:
-All fresh Amsoil synthetics, front to back; Diffs, trans, t-case, motor, p/s...
-Front only steel RCI skid plate.
-OEM plugs
-OEM timing belt and water pump
-Serp belt
-Filter box mod to get rid of that second filter thing.
-Cleaned MAF
-Checked calipers for sticking.
-No codes
-Runs good,

I've got 265/70r17's and FJ springs for it, but they aren't on yet. DT midpipes and Borla catback waiting as well.

I'm not expecting 20's, but 14 is getting old..

Is there something else I'm missing, like a bad upstream 02 sensor that isn't throwing a code?

Appreciate it guys.

 

[Burt]

I think 14 mpg is normal fr the V8. Ever consider a commuter vehicle?

 

[AuSeeker]

I'm all stock as well, 190,000 on the odometer, avg driving speed according to the computer readout is around 32 to 35 MPH and get 16 to 17 MPG consistently manually calculated, computer readout say 18.2 MPG, no highway driving for the most part, but when I do go on a trip where I drive at highway speeds it goes up to around 18 to 19 MPG manually calculated, computer says 21+ MPG.

Mine is a 2004 V8, not sure what your issue is but I would say it's not normal, you need to check fuel deliver specs, i.e. fuel trims, fuel injectors and ignition coils for proper function.

 

[ElDuck]

Mine is a 2004 V8, not sure what your issue is but I would say it's not normal, you need to check fuel deliver specs, i.e. fuel trims, fuel injectors and ignition coils for proper function.

Yeah, i need to figure out how to test those. I passed on a few 04 V8s for the "better mpg" 05-09 V8s. That's the mileage I was hoping for..

 

[ElDuck]

I think 14 mpg is normal fr the V8. Ever consider a commuter vehicle?

Yes I have, but I don't think the break even point with maintenance of another vehicle, the cost itself, and high Michigan insurance rates would be anytime soon. I have a Jeep Comanche that gets 16mpg, maybe I'll start driving that . And a FJR1300 for summer.

 

[Zed33]

I just picked up a mildly lifted v8 4wd with an arb front bumper/10k lb winch. It gets high 13's. I will be doing some maintenance to it though to hopefully pick it up just a bit.

 

[jcaino]

Could be coils. I would also lean towards calipers, but seems you already checked those...

We got our 03 last year with 115k on it and did a trip from Pittsburgh to Minneapolis and averaged 19 (hand calc) with no lift and Michelin ltx tires in the stock size. Speed was probably about 75-80 the majority of the time.

Now with the lift, skids, and aggressive ATs, we see about 16-17 on the highway and about 14 around town.

 

[swanny]

Along for the ride here. Our 2006 has been getting worse and worse, it was around 18mpg when we purchased it in 2012, we are down to around 14-15, no matter what kind of driving these days. Sure it's got a slight lift and one size above stock, I'd just like it get 16 consistantly.

New coils and plugs were just installed along with timing belt and water pump. What next? The only "saving" grace is it's got 230k, so it's no spring chicken.

 

[BR06run]

As crazy as it may sound a bad battery was causing our 2006 Sport V8 to get terrible mileage. The problem was no matter how much or how long you charged it still drew 10amps. This was putting a load on the alternator causing the poor mileage. I presume it had an internal short in it. Yet it would still start the vehicle. A fully charged battery shouldn't draw more than one amp or two. This probably isn't your problem but it is a simple check to be sure. This was the original Panasonic battery causing this problem btw.

 

[Bumbo]

It sounds like it should be a tad higher by a couple MPG, but it’s not too far off from where I would expect it to be.

Driving style can make a noteworthy impact.

 

[zig553]

I find going 75 mph (120km/h) absolutely tanks my mileage, and that's on a stock 2006 V8. I find I get significantly better MPG going 65 mph (110km/h). Do you have a roof rack on or anything?

 

[ElDuck]

I find going 75 mph (120km/h) absolutely tanks my mileage, and that's on a stock 2006 V8. I find I get significantly better MPG going 65 mph (110km/h). Do you have a roof rack on or anything?

No roof rack. I have small Christmas lights up there now, but those had no noticable affect the past few tanks. Yeah, slower makes sense, but also others saying decent MPG doing 75-80 in a stock 4R.

Driving style can make a noteworthy impact.

Agree. I don't drive it like my grandparents would, admittedly, but it's gets remote started, idles for a minute, then a few miles at 40mph to the highway, 72-75mph for 30 miles, then 55mph for a few miles then I'm at work. Not much acceleration time, but usually shifts around 2500rpm.

As crazy as it may sound a bad battery was causing our 2006 Sport V8 to get terrible mileage. ... This probably isn't your problem but it is a simple check to be sure. This was the original Panasonic battery causing this problem btw.

Mine looks to be a newer Duralast, but hey, worth checking. She did eat an alternator a couple weeks into owning it, but no change in MPG from before to after to current.

Along for the ride here. Our 2006 has been getting worse and worse, it was around 18mpg when we purchased it in 2012, we are down to around 14-15, no matter what kind of driving these days. ... The only "saving" grace is it's got 230k, so it's no spring chicken.

Did you have a code from the coils or cracks, or just replaced to replace? Any change?

At that mileage, seems acceptable, but I'm a bit below half of the mileage you have at 105k.


I think I'm going to reclean the MAF with a newer can of cleaner, TB, pull the battery cables again and check the coils out.

 

[PBCRM98]

I get about 13-16 MPG on my 07 v8 but I'm in SF/Bay area. Majority of my driving is city(a lot of hills) or stop and go traffic. I didn't buy this car for fuel efficiency though.

 

[ElDuck]

I get about 13-16 MPG on my 07 v8 but I'm in SF/Bay area. Majority of my driving is city(a lot of hills) or stop and go traffic. I didn't buy this car for fuel efficiency though.

Yeah, I didnt either. But 14 avg on the highway isn't right. I'm not here chasing MPG for the sake of chasing MPG; I feel there is an issue with my 4runner, or a part that isn't performing properly, and I'd like to fix it so it doesn't turn into a bigger issue down the line; or strand me on a trip.

 

[Zeke588]

I get about 12 mpg at 80 mph. I also have tires and roof rack. Haven't hand calculated in a while though.

 

[apohl17]

[MENTION=448354]ElDuck[/MENTION] Figured I'd chime in - I'm getting low 14's lifted, on 32's, with a rack, bumper, skid, and loaded cooler of Spotted Cow. In sub-freezing temps, no less. OP, you should be getting a tad more. The family '06 V8 in stock form is getting 17 in the same conditions. How do the spark plugs look?

 

[AuSeeker]

Just an FYI on my driving style, when I first got my 2004 T4R it was getting around 15 to 16 MPG MAX manually calculated at an average speed of around 34 MPH on the computer screen, I have a Suburban that gets 16 MPG no matter how I drive it so I was hoping the T4R would be a bit better...so I started experimenting with my driving style, I was driving it sorta like I stole it enjoying the V8 about the same way I drive the Burb, so I started to watch the RPMs and adjusted my driving style so that all of my shift points are somewhere between 1700 to 2000 RPM MAX, I then started seeing at least 17 to 17.5 MPG with an average MPH of around 34, I drove it like this for quite awhile with no change in MPG, I then knew how I needed to drive it to get the better gas mileage, so now I still drive it about the same with the exception of I now sometime push the initial shift point from 1st to 2nd gear up to sometimes 3000 to 3500 RPMs briefly but not too often to get up to speed when there's heavy traffic, so that is why I get the MPG I'm getting now that I posted in my first reply, I also get in and start it and then go, I don't let it warm up at all and it's up to normal operational temperature in about 1 1/2 to 2 miles, I also when on the interstate never drive faster than 75 MPH for very long or the mileage will drop drastically down to around 17.5 to 18 MPG or less if I really push it.

As stated the more traffic lights you have to stop at will also dramatically affect the mileage, I try to time my speed so I don't have to come to a complete stop at traffic lights, with these V8s anytime it's running and sitting still the MPGs goes down quickly, also making several stops and having to turn off and restart the engine eats up the MPGs!!

 

[doofenshmirtz]

Driving style is a HUGE MPG factor in the V8. I get 16.5 - 19.5 with how I drive. My wife gets 12-14.

I drive like I’m trying to hypermile it, and she drives like she’s running from the cops.

 

[Inv4drZm]

I try to time my speed so I don't have to come to a complete stop at traffic lights,

I do the same thing because if I don't, I'm starting from a complete stop, then I have to floor it to hear the V8 and enjoy the 4.88 diff gearing.

 

[nevada]

No roof rack. I have small Christmas lights up there now, but those had no noticable affect the past few tanks. Yeah, slower makes sense, but also others saying decent MPG doing 75-80 in a stock 4R.

Agree. I don't drive it like my grandparents would, admittedly, but it's gets remote started, idles for a minute, then a few miles at 40mph to the highway, 72-75mph for 30 miles, then 55mph for a few miles then I'm at work. Not much acceleration time, but usually shifts around 2500rpm.

the remote start/idling and shifting at 2500 is killing your mileage. I rarely if ever get over 2k.

for sure a different driving style would increase the mpg quite a bit.
I dont run much at 70, but when I do, I still see 19-20. all stock 06 with 130k.