MPG Paranoia

bste3

bste3

New member
I'm afraid I may be being an auto-hypochondriac but...

I have a new 2015 SR5 Premium. I have Goodyear Wrangler A/T Adventure tires, same size, and it is otherwise stock. I've now owned it for about 1 month / 1,000 miles, and I'm getting 16.5 mpgs, which seems at least 2 mpgs too low. I drive a blended hw/city and I warm it up before I leave on occasion, nothing unusual.

Here's the paranoia. I think I smell something rubbing/burning (faint) near the right rear wheel.

Is it possible my parking brake has too much tension in it and it is creating extra friction? How could I test this without taking it apart?
 
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bste3 said:
I'm afraid I may be being an auto-hypochondriac but...

I have a new 2015 SR5 Premium. I have Goodyear Wrangler A/T Adventure tires, same size, and it is otherwise stock. I've now owned it for about 1 month / 1,000 miles, and I'm getting 16.5 mpgs, which seems at least 2 mpgs too low. I drive a blended hw/city and I warm it up before I leave on occasion, nothing unusual.

Here's the paranoia. I think I smell something rubbing/burning (faint) near the right rear wheel.

Is it possible my parking brake has too much tension in it and it is creating extra friction? How could I test this without taking it apart?
Click to expand...

Block up the tires then jack up the rear. Put driveline in Neutral and gently spin wheel with the wheel/tire, try to feel for any drag/rubbing. Then take the wheel off and do the same, look for any rub markings in the wheel well area as well. If the brake pad has been dragging you might be able to see a darker/grayish glaze layer on the rotor, which often happens when a pad is dragging. On most vehicles you can unhook the steel braided e-brake cable with a pair of pliers at the caliper...not sure about the 5th Gen (haven't looked yet) so maybe someone else can verify. Hope you get it figured out.
 
Here are a few things to consider:

Do tires have same rolling resistance as stock?

Are the tires the same weight as stock?

Are you using a winter blend gas?

How long are you warming the truck up for? Unless it's an extremely low temperature you are just wasting gas.

Have any other mods been done at all?
 
Take it back to the dealer. Thats why you bought new. And change back to the tires that came on it. You've changed the tread pattern and type of tire therefore your mileage will not be at it's optimum. You also bought a brick. I get it you wanted a four runner and decent mileage. Well you have both. That is not the worst and it's not the best. If your going by the window sticker on what you should be getting they all lie. Those tests suck.
 
bste3 said:
I'm afraid I may be being an auto-hypochondriac but...

I have a new 2015 SR5 Premium. I have Goodyear Wrangler A/T Adventure tires, same size, and it is otherwise stock. I've now owned it for about 1 month / 1,000 miles, and I'm getting 16.5 mpgs, which seems at least 2 mpgs too low. I drive a blended hw/city and I warm it up before I leave on occasion, nothing unusual.

Here's the paranoia. I think I smell something rubbing/burning (faint) near the right rear wheel.

Is it possible my parking brake has too much tension in it and it is creating extra friction? How could I test this without taking it apart?
Click to expand...

Personally, I think you are seeing a MPG reduction due to a combination of factors, like others have stated.

Colder weather.
Lower tire pressure due to ^^^.
Winter gas formula.
Warming up your vehicle will have a bigger impact on MPG than you think.
Have you reset your AVG MPG lately?

I doubt anything is wrong! I have noticed my MPG drop into the 17's over the last few weeks. It'll go back up in the summer.

Enjoy your ride!
 
Thanks for all of the responses. I'll be putting another 1,000 miles on it this week heading up to Michigan. I set my tires at 38 when I fill them up but right now they're at whatever the tire shop put them at.

I'll check my pressure and reset the guage before the trip. Unfortunately I'm going to have a ski rack on top messing up the experiment, but we'll see.

I warm up the car for comfort, not for the engine, btw.

Also, I am coming off of a 2006 4runner with Destination AT tires where I averaged 19-20 mpgs with my driving, so that's my shock so-to-speak.
 
Antman said:
Warming up your vehicle will have a bigger impact on MPG than you think.
Click to expand...


Is this because the engine is running rich during high idle/cold start? I always warm up my vehicles before driving. The 4Runner takes a much longer 4-5min compared to my Rav in 2min. I could see warming up a vehicle for 10+ min in freezing weather taking a MPG hit.
 
You instantly lose around 10% (say from 20 to 18 mpg) just by taking your data this time of the year compared to the summer months because of the gasoline blend changing every October.
 
st8rocks said:
Is this because the engine is running rich during high idle/cold start? I always warm up my vehicles before driving. The 4Runner takes a much longer 4-5min compared to my Rav in 2min. I could see warming up a vehicle for 10+ min in freezing weather taking a MPG hit.
Click to expand...

You are burning fuel without going anywhere so your miles per gallon would be undefinable because you can't divide zero!

Your vehicle will run rich on cold start whether you are sitting in the driveway or driving down the road.
 
For day-to-day mixed driving in the winter anything above 16 is not bad. Anything above 17 is a bonus. Sitting around 15.5mpg on my current tank.
 
I'm getting 17.6mpg per the computer with 285/70/17 duratracs and a lift.
Was getting 19.6 stock.

Not sure about winter gas in Arkansas though.
 
Oddly enough; I've been getting better MPG lately; maybe something to do with gas here in AZ; averaging about 20.5 mostly highway but with stop & go traffic on the lovely I-10!
 
I read these posts with amusement, too many variables to compare depending on the fuel type ,ambient temps , terrain and so on everybody will achieve different numbers.

My Trail is bone stock, since new averaged 15.1 mpg and gone as low as 13 in the city. Taken off road it has dropped to 9 mpg.

No clue how you guys drive to see 17-19 mpg.
 
Stock 2015 trail here and I'm averaging 19.4mpg with mixed driving. I don't drive like a grandpa, but don't drive like a high-schooler either.

I'd be willing to bet that letting the truck idle in the driveway for 5mins every time is a major contributor. That will really kill the mileage. You are paying for the comfort in the form of gas. ( doesn't hurt anything, keep doing it if you like, just know that you're burning gas).

The smell is common per the above thread links.
 
I've owned 3 4runners and a Tacoma. A2006 Tacoma, 2008,2011,2013 4runner and now a Trd Pro. Live in the mountains and commute 86 miles each way to work. I run stock size Kelly Tsr's. I have always gotten between 21 and 22 miles per gal. with all of them. With the current Pro I'm averaging 21.6. I lose several tenths when I'm in 4wheel drive.
 
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