Toyota Tundra Discussion Forum banner

5.7 towing mpg

34K views 25 replies 19 participants last post by  edc1911 
#1 ·
HI I am new here and got a tundra a few months back. Great truck overall!

Just a bit disappointed in my towing mpg. Done a lot of reading and searching and have accepted these dont get good mileage.

With that said when you are getting 6-9mpg towing/ and 13-15 when not, a little change makes a bigger impact in the wallet.

So mine is a 2008 5.7 with the towing package, I am pulling a roughly 30 ft toy hauler that is between 8-9K pounds loaded up.

The truck is all stock with about 100k on it, the only change is that I put on 275/70/18's when I replaced the tires instead of 275/65/18's .
Does anyone know if that makes much if any of a difference in mpg? primarily when towing

Was considering some aftermarket performance stuff, but only if it helps with the mpg, really dont want to spend the money and make this thing noisier if the extra power doesn't result in some better mpg.

Seems like a lot of people end up selling their cai and spacers due to noise. I've done plenty of performance mods to cars over the years and had fun with it, but At this point the extra money is only worth it to me if gets put back into my wallet at the gas pump.

Also read a bunch of stuff about whether to tow in tow haul mode, full auto, or manually selecting the gear. As well read something about turning off the nannies? asked a few people about that they had no idea.

any thoughts or help is greatly appreciated.
 
See less See more
#2 · (Edited)
Yes the 275/70r18 will affect your mpg. My 275/70r18's are 10 ply. So even my empty mpg went down. But don't forget thet your mpg are off because of the size diffence. Maybe not a lot but some. I tow a 16 foot flat bed with a Jeep JKU weighting just under 7K. I use tow/haul mode on and S5. If going over the hills S4. It it starts hunting for gears on steep hills then S3. I've gotten 11.5 mpg on freeway driving hand calculated. I have found any speed over 65mph and any hill my mpg tanks fast. But my 2013 Ram 2500 Cummins didn't get that much better at 13mpg. Plus it need DEF fluid. Remember to check and air up your tires. I run roughly 40psi front and 45psi rear on truck and 60psi with load range D on trailer. None of the after market stuff will really help your mpg. You will spend more for part with no real return from what I've read.
 
#7 ·
thx, any idea how much your mpg dropped with the heavier/larger 10 plies after you factored in the difference it made to the odometer(think roughly 3%)? I know I can't get close to your mpg as my load is heavier and has more wind resistance, but I'd love to be in the 8-10mpg range
 
#4 ·
I have a 2015 DC SR5 TRD with the 5.7. I don't tow a large trailer, only a utility trailer that weighs 1000 pounds empty.

MPG on the last tank was 16.8mpg with no trailer towing. If I hook the trailer on, it drops 2 MPG even when the trailer is empty.

You're towing a much larger unit, and not only does it weigh much more, but it probably adds a lot drag in terms of air resistance as well.

Both my first gen tundra (4.7L) and now this one seem to be much more sensitive to air resistance in terms of negative impact to MPG. Drive into a strong wind all day going on a trip and the MPG drops significantly. For example, coming up across the southern plains last weekend with the cruise set at 75 mph, I got over 17 mpg with a strong tailwind. I know from experience that if I was going the other direction into a headwind, my mileage at that same 75 mph would have knocked the mileage down to the low 15s, perhaps even upper 14s.
 
#5 ·
I just got back from hauling a 27' 5th wheel camper. 9.2 mpg recorded.

I actually filled up before and directly after the trip because I wanted to know what I truly got dragging that camper.

I did have a killer headwind the entire trip. I was pretty happy with the number recorded. I have not had a chance to fill up to find out what I got on the return trip. There was no head wind. Just looking at the gas gauge, there is more gas in the tank, so am anticipating even better numbers.

I find that the truck really likes 4th gear and 67 mph. This keep the RPM's at 2900. I can run with the cruise on and the truck does not downshift when running up the hills on the xway.
 
#6 ·
Just pulled my boat to the coast and back, 500 miles round trip. It was my first tow with my '13 CM. I've been getting 17.5 without towing. The first half of my trip down to the coast (and last half coming home) is hilly, then it is flat. I averaged 9.2 mpg on the entire trip. Boat has a fairly large frontal area, compaired to some boats, with a high center console and T-top. Boat and trailer weigh 4650#. I drove in S5 w/o tow/haul at 60-65 mph on the I-10/I-37 route.
 
#10 ·
Just took my new camper out west a few weeks and got only single digit mpg. I have 2013 dc 4x4 with 275/70/18 at3's. Pulled 2017 open range ultra light 2604rb. Uvw is around 5600 lbs. Probably had a total of 7-7500 lbs. total weight. Started in KY went to Utah. Total miles was over 3800. Lowest average was 6 mpg, best around 9 mpg. No problems pulling. Glad I had transfer flow 46 gallon tank.
 
#13 ·
No fuel filter.....I have P rated tires on my Tundra - I set to max PSI on side wall towing or not and my MPG's are alittle better 14.6 - 15 on highways 35 - 40 mph.
Towing I get 8-9 mpg only <5k toy hauler @60-65 mph. 60 is the sweet spot on mpg's......

Plugs will help - tire pressure will make a bigger difference - and proper size - vehicle is sitting level vs nose hi.

Cant control weather - headwinds kill mpgs all you can do is slow down.
 
#14 ·
Hey could I get some more info on your toy hauler??, interested in buying one thanks
 
#15 · (Edited)
2015 Forest river grey wolf 19RR limited


Just enough for my wife, two labs and my self.
Bike fits also
2006 Goldwing

Dont ask me why pics upload upside down.
 

Attachments

  • Like
Reactions: Muleycrazy13
#17 ·
Buy an eco BS if you want better towing mileage! Oh wait they dont!
2015 3.5 ecoboost towing mpg

Just seeing what others are getting while towing with their 2015? I have towed my toyhauler (6500#) several times and have just over 5000 miles on the truck and at best have got 7 mpg. Took my truck back to the dealer, as I have only had the truck a little over 2 months, and there was an update already. Most towing at interstate speeds 70-75. Truck is stock except a 4" MBRP cat back.
Nice most trailer tires are rated @ 65 OMG
 
  • Like
Reactions: Muleycrazy13
#18 ·
Well you don't buy a truck for gas mileage you buy it for work. As long as the truck gets you and your family to your destination and home safely the cost of fuel shouldn't really matter. I haul hay, horses, kayaks and use mine to commute to work when the weather is bad. I average around 15 empty and 9-10 when towing my two horses or hay around town. I have a 07 D.C. that I did the same plus tire size change this year. I didn't really notice a difference in mileage when I changed the tires. I have a friend who hauls almost an identical load as me with his F350 and he only gets a couple mpg better than me when towing. His maintenance cost is more than twice what my truck is. At less than 100k on his Ford we have put in a transmission, rebuilt his rear end, and a turbo. My Tundra has 120k and the only thing replaced so far is a water pump. The biggest problem I see when guys are towing is they have a heavy right foot. Just because your truck CAN tow at 80 mph doesn't mean you should. It infuriates me when I see a guy with a diesel hauling horses going 80 mph down the road. I never exceed 70 mph when towing empty and never above 65 when hauling hay. When I have my horses I never exceed 60 mph.

As far as getting better mpg there really aren't any mods that you will ever get your moneys worth. Most mods increase HP which more power never increases mpg.

Just my two cents of course.
 
#23 ·
I am pulling a roughly 30 ft toy hauler that is between 8-9K pounds loaded up.
^^
This is why you got single digit MPG. New trucks (8 years newer!!!) probably wouldn't have done much better than you. This is one of the reasons I love my Tundra!! Push comes to shove this 9 year old tech is still competitive.

Just finished a 3100 mile trip from OKC to northern MN to estes park CO and back to OKC. Pulled a pop-up camper (loaded with gear maybe 2800lbs) Trip avg was 12.8. Best was going up to MN and was 13.5. I set the cruise on the speed limit with the exception of SD where the limit was 80mph. I used Tow Haul mode with the exception of coming down in from Estes Park where I used shift mode (managed 16.5mpg that tank). When pulling the boat to and from the lake I am right around 12 mpg.
 
#24 ·
Pulling my 28' TT 6500ish lbs from Indy->Ft Wayne, I only got 8 mpg while going 65 mph. My biggest issue is that the gas tank on these trucks is too freaking small... I don't want to have to stop every 200 miles, but taht's what I'm stuck with for the time being.
 
#25 ·
The last couple of times I have pulled my 14ft utility trailer loaded with hunting gear and a couple of atv's, I averaged around 12-13mpg driving I-40 to Eastern NC. I can average 16-18 hwy and 14-15 city unloaded with a 16 Crewmax and stock 18inch wheels. The only mod that may affect it is the AFE dry filter I installed.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top