Gas Mileage with a GFC Tanked

Something must be wrong with your truck bro, I average 24+ with a 3" lift, 285's and a topper if I can keep it under 75.

Before I pulled the trigger, I read around here a lot and my selective vision and optimism had me believing I could expect 21-22 MPG, maybe better, so long as I didn't mess with it too much. The reality is that I'm getting 17.5 bone stock (OK, well I do have one mod - bumped my tire pressures up to 35 cold), driving like a grandpa with a 50 mile daily commute, which is about a 50/50 mix of 50-55 MPH secondary roads and 70 MPH highway. You're not really doing THAT bad, I don't think.

 

I can only get over 20mpg with 285's in hot weather (80+) and keeping speed below 70. winter time im lucky to get 15.

 

17.5 in stock TRDOR here (25Kmiles)...I think you're fine.

 

You do also know that (and states do vary some) - winter blend gas (which has less energy per unit of gasoline) runs from some time in September through April right? It's not uncommon to see 20 mpg turn into 18 during that time as well...with doing zero mods whatsoever. Assuming your fuel that you ran into Oct 2022 was purchased before that changeover, this accounts for a large portion of the decrease you have noticed.

 

Gears will not improve highway miles.

 

Exactly the same, even a stock TRDOR. The only time I ever see 18-20 mpg is driving 65 mph or less on flat roads. Head winds, hills, 75 mph, stop and go, which is my usual driving ... 17s all the way.

 

Appreciate the feedback from everyone… starting to feel better about it haha

 

I was getting 16 stock, 14 modded, 13 with gears and the gfc.

 

Do you think the sliders gain was due to wind drag or weight or both? I'm thinking aluminum instead of steel ...cost more but weigh less.... if wind drag then maybe I should stick with cheaper steel.

 

I used to try everything to get the most mpg out of my truck but I might suggest you just run a quick calculation in excel of your annual mileage and any mpg difference you have. For me I found it was trying all sorts of stuff for about $300 bucks a year difference... which isn't much at all so now I say whatever and just have fun =)

 

The weight isn't the issue. My Tundra got the same mileafe towing my utility trailer empty as it did with a 1400 lb. RZR on it. The ramp at the back was what killed it, not the weight.

You added a bunch of aerodynamic drag and thats an exponential problem. The faster you go the more it inhibits you. Drive slower and it'll help.

 

A number (your speed) that is squared is an example of quadratic growth, not exponential growth, FYI. The difference is whether or not the exponent (the square in terms of velocity) is a fixed constant or not.

 

Apologies for not being technical in naming the growth when trying to convey that the punishment for increasing from 10 mph to 20 is less than the punishment for increasing from 60 to 70.

 

I have a MT Off Road as well and with an Uptop Roof Rack, Bed Rack (with the Alpha Cap) and a loaded Decked in the bed I'm getting 17.5 MPG on stock tires and suspension. And considering most Texas highways are often 70-75 MPH (which means everyone is going 80-85) going below 75 typically isn't an option unless you want to get run over.

 

To help yourself be a happy Tacoma owner, never look at MPG. Just fill up the tank as needed, and roll on. Works great for me.

 

Yeah not buying this at all.

 

For most this is probably the case, but it isn't always 100% accurate. I'm coming from a 2nd gen, but in my case my truck is stupid heavy and pulls a trailer to boot. In mountain passes, stock gearing I was in 3rd, sometimes even 2nd as 1-4 were all that were usable (5th gear? yeah, might as well have not had it). I went from 3.73 to 4.56s (and only upped to 265/75r16 on tires) and I'm now able to use all five gears again. I'm not constantly dropping to 3rd screaming the motor, but instead able to downshift from 5th to 4th and stay at a reasonable RPM, and only dropping to 3rd on really steep stuff. Overall ratio is more usable in my situation, which is not the norm. My mileage is horrible unloaded, hahaha, but the drop is significantly less loaded than when I had stock gearing.

And for anyone not happy with 16... unloaded on 100% hwy i'm about 13.5 if i'm lucky. Average 12 unloaded. Loaded fully I've seen 6.5 to 8 depending on whether I'm doing 65 or 85

 

theres a thread around here, maybe in the toppers and covers area, but someone did some mock up drawings in some software that showed the wind resistance of a tacoma with nothing on the bed, a tonneau cover, shell, gfc, 4wd camper, etc.

it was a massive difference from a normal shell to a gfc/4wd camper. enough to expect a noticeable drop in mpg.

i looked around but cant find it right now