Added weight VS. M.P.G.

I'm about to add some weight to the truck.
At 18 MPG w/300 added lbs., at 2% reduction per 100lbs, = 16.92 MPG.
Not bad, right? The approx. 110lbs front bumper and 124lbs skids I'm going to put on won't get me into that bracket of 6%/300lbs added range, but the sliders and rear bumper surely will and then some.
I'm just curious, does this seem accurate to others?

 

I prefer the 0.1second/100hp on the quarter mile time rule.

 

When my mileage drops to the single digits I might get concerned.

To see what has been behind my seats for the last year or longer

In a pure perfect world your numbers might be correct so many other things influence mileage.

 

Like the thread because I’d like to crunch the #’s as well cause all my stuff is do to arrive any time now and probably over 400 lb

 

I hear you. I'm in NM and CO and will be doing rock-hounding trips. So, I'm not a 'rock-crawler' but there are PLENTY of rocks. I'd like to try to get a happy medium between armor protection and mpg. I think the 2% reduction per 100lbs isn't that bad. and I also hear you about all the other factors.

 

Right on, what's coming in for you soon? I'm thinking the 2% per 100lbs isn't that bad. Take your mpg and reduce by 8%, to compensate for the added 400lbs

 

I can't really afford aluminum, nor am convinced that's the way to go. I am considering 1/8" steel skids, but will probably go with the 3/16". The 1/8" weigh 83lbs, the 3/16" 124. diff. of 41 lbs, less than 1% reduction in gas as per equation, lol, argh

 

I averaged what was it...18mpg or so with rear bumper, sliders, bed rack, and roof top tent?

Depends where you drive, and more importantly, how you drive.

Like someone mentioned, start worrying if you hit single digits. These trucks are old and will not run as efficiently as newer models do.

 

Rock sliders front and rear bumpers swing out tire carrier skid plates for motor and tranny roof rack and winch
Hey bro if you are crawling around in rocks to find rocks doesn’t that make you a rock crawler?

 

Where did that math come from?

I mean, maybe as a general rule of thumb you'd expect some reduction in MPGs with added weight, but that's an oddly specific calculation.

IMO, you're overthinking it. Sure expect some reduction in MPG, but if you're trying to calculate what that reduction is going to be before you commit to doing the modifications, it's best to just leave it stock, and maybe not even start with a Tacoma in the first place as these things aren't known for their gas mileage.

That said, there are many more variables at hand that determine your MPGs. It's mostly that thing that's connected to the bottom of your right leg, and how hard it pushes on the skinny pedal. People here claim to get 18mpg with 33's and all sorts of armor. Either their math is off or they drive like a grandma.

 

2% is what Google tells you when you search "reduction in gas mileage per 100lbs" .... from personal real world experience with this truck I can tell you that number is WAY to low. First most important factor is what @jbrandt says "how hard you push that skinny pedal".. i drive like a grandpa, anything over 55mph scares me. Second is accessories on the outside that ADD drag.. like a roof rack .. third is going to be your extra weight.


I rebuilt my motor and transmission, driveline and steering components..so EVERYTHING is new, like it rolled off the showroom. Before I added any weight whatsoever, with my slow to accelerate skinny pedal pushing and 3.56 gears rolling on 31s, my gas mileage average was 18mpg CITY per tank.

I added 400 pounds of weight(no armor, just tools and cap and camping gear) and I went down to 16.2 city.

18-16.2=1.8mpg


1.8mpg÷4(x100lbs)=.45mpg LOSS per 100lbs added weight

Expect this number to change on a non linear progression per extra 100lbs extra

 

2% is what Google tells you when you search "reduction in gas mileage per 100lbs" .... from personal real world experience with this truck I can tell you that number is WAY to low. First most important factor is what @jbrandt says "how hard you push that skinny pedal".. i drive like a grandpa, anything over 55mph scares me. Second is accessories on the outside that ADD drag.. like a roof rack .. third is going to be your extra weight.


I rebuilt my motor and transmission, driveline and steering components..so EVERYTHING is new, like it rolled off the showroom. Before I added any weight whatsoever, with my slow to accelerate skinny pedal pushing and 3.56 gears rolling on 31s, my gas mileage average was 18mpg CITY per tank.

I added 460 pounds of weight and I went down to 16.2mpg


18-16.2=1.8

1.8÷400=.45

So thats a reduction of .45mpg per extra 100lbs of weight.


18÷.45=40%

So im dropping 10% gas efficiency for every 100lbs of weight I've added

 

That's damn good with all that hardware it seems, your mpg I mean. Right on. I know what you mean about 'how you drive', suppose many relative factors. after finding out the mpg reduction relative to weight I'm not as concerned. But I will be adding more weight, haha, and I know it will f'n add up.

 

For sure, your logic computes, haha. Love crawlin' around on rocks. Gotta do it while I can

 

I hear you, but for sure sticking with this tacoma. I'll work on not overthinking. Love this truck

 

I very much appreciate the information, notes taken. I'm like you, I drive slow. Especially at night. We are f'n inundated by elk here in northern NM, hence the ARB front bumper soon. I see what you mean about the 2% being way low. That's bad-ass you're mechanic and can do all that work on your rig yourself.

 

I added an ARB and skids and didn’t see much change. Biggest was getting skinnier tires and aluminum wheels

 

Everything is a compromise. Just build your truck the way you want to, and don't worry about the MPGs.

I mean, track them every once in a while so you can see if something might be wrong, but honestly if we all worried so much about MPGs none of us would mod our trucks, especially for off-road.

Like, if you don't do serious offroad rock crawling/bashing type stuff, you don't need 1/4" steel skid plates, but you probably still need something. Maybe the stock ones are fine (for most people, they are). I ran for many years without rock sliders, it was only in the last couple years that installed them. Mostly due to the fact that it's a dedicated trail truck now, not a daily driver.

 

I think F1 has a $10,000,000 a second rule, or something like that.

 

I am not sure about the weight calculations, but I do agree that lighter is better. What front bumper are you putting on?
I have a 2006 GX470 and I just removed my Demello Off Road front bumper, maybe 150lbs. Put my original front bumper back on and my fuel mileage went back up by 2-3 mpg on the highway. That is all aerodynamics drag, so you should also think that.

I do a lot of long trips and every MPG can make a difference, so my next build will take a serious look at weight.