Gas Mileage Off Road

Does anyone have experience with the fuel efficiency of their Tacoma on extended off road drives? I'm planning a trip that will be at least* 270 miles between gas stations, 240 miles of that off road. I haven't been to the area before, so I don't know the road conditions. I expect most of it will be decent dirt roads, but at least a few miles is mild(?) rock crawling, and there are some sections of sand. I'm bringing a 5 gallon jerry can, but is that enough? Assuming 18 gallons is usable in the tank, that's 23 gallons total available. I need to average at least 11.7 MPG. Will I make it, or do I need to bring more gas?

I have 265/70R17 load range E tires, which will probably be aired down to around 20 PSI for most of it, and I'm bringing a few hundred pounds of camping gear (including at least 10 gallons of water and 5 gallons of gas).

*270 miles is the shortest possible trip. If I can make it an extra 20 miles at the end of the trip I'll save 35 minutes and $12 on gas. And there's at leas one 35 mile round trip detour I might like to make, but I don't have to.

 

I would plan in bringing more gas to be safe. Too many unknowns

 

Sounds like an interesting trip! A single 5 gallon can will give you an extra 60 miles at least- you aren’t pulling a trailer so plan on 12mpg or better. Are you doing the Dempster Hwy?

 

It's hard to say exactly, I keep an eye on the mileage screen when offroading and it only really changes when going uphill, or really slowly over technical sections. Sorry for the metric units, but its an 80L tank, and I usually get 10L/100km on highway. 800km is 497 miles, which is almost twice the distance you're doing. That being said, I have a 25L (6.6 gal) container that I keep in case of emergencies.

Short version, from the numbers you've given it seems fine, and the extra fuel is good to have just in case.

 

Not the Dumpster highway (but that would be cool). I'm going to Utah, spending 5 nights camping. I'd rather not say exactly where, but it must be one of the most remote areas.

Maybe I'll also bring the 2.5 gal gas can for my lawn mower and stash it in the desert, just in case.

 

I always finish a trip with extra fuel and water, much better than the other way around.

 

I have the same thoughts. Can always use the gas to fill up after the adventure.

 

best way! by design!
Both are a necessity, I would skimp on weight elsewhere.

 

(Tank usable + gas can) * (estimated mpg)
(18+5)*(11.7)=269miles.

On paper it looks good. It’s hard to estimate the average mpg & how much extra fuel is needed. Terrain, weight of gears, road block & need to detour, going off course intentionally or unintentionally (I have a few time lol), and other unforeseen situations will affect your estimate.

I’m on the same page as @islandhiker, I always bring a lot more gas on long off-road trip then needed due to unforeseen circumstances.

I’m average at 9-10mpg most of the time when off-roading. If that were me, I would bring at least 4-5 gas can.

 

Why do you say only 18 gal? Your truck has a 21 gal tank. It's not recommended to take it down to empty, but an occasional run down to 1 gal isn't going to kill your fuel pump.

 

Probably accounting for last gas station fill up - travel to start if off-road area. 3 gallons of so, roughly 30-45 minutes of driving after fueling.

My only guess.

 

I haven't had the truck long enough know what is the comfortable usable capacity, so I was guessing 18 to be safe. Sounds like 20 is reasonable. My 4Runner had a 23 gallon tank, but I never put more than about 20.5 in it. I don't like driving past when the distance to empty hits 0 miles.

 

It’s an estimate by the time the empty light goes on? Anyway, it’s an estimate only. Using 21 vs 18 in this case, you get a bit more range. But going off-road for 240miles, too many unforeseen therefore I believe it’s better to use a lower number to estimate. This way, if you come out with some fuel left, it’s a win! If you use a higher number to estimate and you ran out of fuel near the end, you get the point. It’s a win win to have more fuel.

Harming your fuel pump or not is a different topic on a different post. But everyone can pump when ever they felt comfortable.

 

Seems like I usually get 10-12 in the dirt, but stuff happens. Getting stuck, having to remove trees and depending on how you get out can reduce it. At a minimum I would take the extra 2 gal. and 4-5 would be better. Depends on how far you will be for calling for help/gas. I have put 19-20 gal in my truck more than once, just to see how far down it will go. I think you could count on 20 plus before running out. Also please have a good satellite communication device in case of emergency.

 

To OP. Top gas tank off before you go. Best use “common sense.” Are going only one truck, with a group of 4x4? Bring extra gallons of gasoline just in case, never know, better than being stuck someplace.

 

I'll obviously fill it up at the last gas station. I'm planning to take a 40 minute detour (20 minutes in the wrong direction) just to get gas 20 miles closer to the start of the trip. Already accounting for that in the 270 mile total.

I'm not traveling in a group, but it's not so remote that no one will pass by if I have a problem. The more traveled areas probably see tens of vehicles per day. There's one remote campsite 20 miles off the main road that probably nobody visits unless they are camping there, and that's the only place that seems dangerously remote. I have a PLB in case of a life threatening emergency, and I was surprised to learn that there's actually cell phone service in some areas (not counting on it of course).

I guess I'll take 7.5 gallons. I don't like carrying fuel, and I don't have a good way to attach it to my truck yet. But it's better than running out.

 

Sent you a PM because I think I know the trip.

 

This.

/thread

 

Just an update. I went 291.7 miles and used 22 gallons. The dirt road in and out of the area I visited was smoother than some highways, so I was doing 45mph averaging over 20mpg for the 150 miles on the way in and out (about half dirt half highway). Most of the off road segments I averaged around 10mpg. For the rock crawling that took me two hours to go two miles I got around 2mpg. Or in other words 1 gallon burned there, mostly idling while I jumped on to look at the next obstacle.

EPA gas cans are really awful. I spilled gas a couple times thanks to these stupid things. The first time was sort of my fault. I forgot to vent pressure from the lawnmower has can before attempting to fill the truck. It sprayed gas forcefully, and only a little made it into the tank. Thankfully that was at home before the trip, so I could clean everything up. On the trip the lawnmower gas can started leaking somewhere around the spout as I was fueling the truck. The brand new spout for the brand new Wavian Jerry can was awful too. It bound up, requiring extreme force to open. I broke part of the plastic off trying to press it against the filler neck. I didn't spill much, but it took me probably 10 minutes to refuel. The truck does not like to take gas poured in from a portable can, and it spills if I go any faster than extremely slow.

I'm thinking if I take the spring out of the Jerry can spout, it might be usable. Or maybe I should use a siphon or funnel instead of just the spout.

My idea of using a hitch mounted winch carrier for the Jerry can worked okay, but it scraped on a lot of stuff. I underestimated how much it would get in the way. I need a better way to mount the can somewhere. Maybe a roof rack.

 

Neat