Post your mpg

... ^^^ ... Thanks ... I will go back to 91 on this vehicle and give it a try with my "clunk" ... your post made me curious.

 

yeah try the 91 for a few weeks to see what happens.
this may be a repeat...did you check the trans oil? many produced low from factory causing that "clunk" you refer to.
give it some time (2500-3000 mi) until you start to really feel the truck out.

I'm pretty happy with it now.

 

IMO for your consideration...my 2016 gets the same mpg on either octane...Car and Driver Magazine once did a test and one sample car actually suffered a decrease in mpg using higher octane...

"...Time and again, people will be told that high octane fuel burns cleaner or more completely, and that it will give them extra power and better fuel mileage than Regular octane gasoline because it contains more ‘energy.’ These blanket statements are simply not true. In fact, the octane rating for gasoline has nothing to do with the amount of power locked inside of it – it actually relates to just how much a fuel can be compressed before igniting. The higher the number, the less likely it is to ignite under pressure."

 

2x2 AC sport TRD w/ removed air dam, 19-20 MPG combined, FWY/Street driving

 

Out of curiousity, are the DCLB's getting any worse MPG than the DCSB? I know weight difference is only like 70 lbs or something so I don't imagine it could be much.

 

when did you start using the 91 octane? I assume it was when the refineries changed from winter to summer blend. The higher octane did not increase your mpg. Something did. It may have been you trying to get better mpg when you switched to 91. You probably didn't notice, though.

Also, air isn't going through the filter box very quickly. Taking out that screen will not give a noticeable increase in mpg

 

4x2 DCSB TRD Sport with the air dam removed. I'm very pleased with what I've been getting.

 

My trip meter reset on its own, so my tank avg was at 29.6 mpg. I get around 28 mpg going to work since its mostly going down hill.

 

If there is anything that is more misunderstood than octane ratings I would be amazed.

Most people disregard all the electronic measures current engines use for air/fuel/ignition management. IF the engine did not have these advanced electronic controls the statement would be true (within reason, using typical good quality pump gas) However, just because the engine management system will allow use of 87 octane fuel, it doesn't mean the engine is optimized for 87 octane.

The engine management system will adjust ignition advance fuel delivery to prevent pinging at the cost of fuel efficiency. The 3.5 has an 11.8:1 compression ratio and an under square bore and stroke (larger bore, shorter stroke) Short stroke engines tend to rev higher, long stroke motors tend to have lower RPM torque. Yet the 3.5 doesn't feel like it wants to rev until it gets above 3500 RPM, I am assuming that is largely do to the variable valve timing trickery of the simulated Atkinson cycle. The slower the engine revs, the more time the cylinders have to fill, which goes a long way towards reducing engine pinging, so perhaps the 3.5 has more latitude on octane choice as far as spark knock. However, that doesn't mean it's performing at it's optimum under those parameters.

I'm in the 91 runs smoother and pulls a little harder camp. It's a subtle, yet noticeable difference.

Originally I thought that I was deceived by the placebo effect of using higher octane fuel, or that the engine was smoother because it was "broken in." I went back to 87 for a couple of tanks.
There is a difference by my experience. Am I doing a Jedi mind trick on myself? I don't think so, but I suppose it is possible.

Totally agree about the air box/filter. The effort put into designing the air intake system to work across all RPM/engine loads is considerable. Unless the engine is highly modified from it's original configuration, you will only make it worse jacking with the intake.


I

 

Also hit 1k miles

 

Sport 4x4 dcsb auto stock- I get what the sticker says 18/23. Really doesn't matter if I get on it or granny it. The shifting did get better at about 900 miles...

 

I bet a lot of it has to do with speed. I usually cruise around 60-68, slower highway speeds here in Oregon. But once I jump up over 70, things get bad, in a hurry.

 

I just got back from a 1900 mile trip and averaged 23.1 mpg (US) per computer. Best tank was 25.0 from Klamath Falls, Oregon (elevation 4100 ft) to Santa Cruz, California (sea level), obviously mostly downhill but crossing several 5000 foot passes on the route, AC on most of the time, and several rest stops. DCSB TRD OR, auto trans, 4wd with cab-high shell, all 87 octane gas, finished trip with 9100 miles on the odometer. Mostly highway driving, but quite a bit of heavy urban traffic in downtown PDX, criss-crossed the Cascades several times, including Forest Service back roads, and even did a few hundred yards in 4wd on a snow covered forest road. I used cruise control a bit, but found that at 65 (most of Oregon plus "urban freeway in CA) it tended to use more throttle and unlock the torque converter (or downshift to 5th) with higher revs than if I managed the skinny pedal myself. In the mountains I played with ECT and S-mode shifting quite a bit. I also played with the higher rpm's a few times passing trucks on US97 ... high end power is not a problem with the 3.5

Other observations: the average over less than 100 miles is meaningless. Just starting off from a gas stop and reset, and getting back on the freeway would drop the average into the teens for 10-20 miles. Headwinds up I5 in Northern California had me at 17 mpg at 70mph for over 50 miles after one refueling stop. Conversely, from Klamath Falls southbound to Winters on US97 then I5/505, running at 70-72 with the AC on most of the way, I averaged 26+ (maybe 250 miles), but by the time I went through the Bay Area in rush hour, it dropped below 25 total for the tank, then recovered to 25 on the downhill into home. Still, I easily got 400 miles on that tank. I made two brief stops on that tank and my butt felt fine when I got home, not something I usually find after a day in the car.

 

have someone randomly fill up your tank and keep a log and then keep a log of what fuel you think is in it. Do this a few times and then compare logs

 

3rd fill up this morning including the full tank from the dealer. MPGs have improved with each fill up. I'm just over 500 miles. This morning my 15 mile drive to work with 60% highway I got my highest return yet just shy of 24 MPG. ORDCLB using 92 octane. I am coasting when possible and trying to avoid the urge to step on it for maximum torque. Just shy of grandpa driving. When I want more power, I use S gear mode and shift manually in the low gears 2-3-4. I tried ECT a few times, but I don't want to use it full time.

Here's a hint... switch to neutral in most coasting situations. When you are in gear and coasting, you can feel resistance from the engine and RPMs are slightly higher. When I switch to neutral, the only resistance is the bearings, tires on the road, and the weight of the truck.

 

I have been getting 21.5 at tank fuel up old fashioned method 75%city 25 % hwy. The mpg on this truck is better than I expected considering it is a dcsb manual 4x4 off-road.

 

Made a 175 mile round trip run to see my Dad today.
No cruise control, AC on and nothing but back roads, small towns, etc... the whole way.
Trip avg. was 24.8. I'm a happy camper.

 

Highway: 18MPG
City: 16MPG

285/70/17
3" Lift

 

anyone know if it's possible for the ODO to show decimals?

 

On average I'm finding the Truck MPG tracking is off by about .3 MPG favorable...so the truck is showing better fuel economy than its actually getting. Fuelly and hand calculations tell the true story.