Tire Poke Gas Milage Drop

[Gator 22]

I have been wondering if tire poke leads to noticeable milage drop. I see a wide variety of posted fuel milages listed in various post and wonder how much poke contributes. On my first gen 4Runner I had large poke, big tires, large rack etc. and fuel milage dropped considerably. I don't remember specifics (it was the 80's) but I do remember a drop. Adding bigger tires, heavier tires, large roof racks, molle panels, winches, and large poke all contribute to lower fuel milage. How much does poke contribute to the equation?

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[gvan1998]

Tire poke will create more air resistance.

 

[FoRunna]

Yes. Pushing the tire outside of the fender will cause a noticeable drop in mileage.

Basically, it creates aerodynamic drag. Where the wheel would normally be inside the fender well, it is now positioned outside the fender and is interrupting air traveling across the side of the car.

As far as how much it affects it, that depends on a lot of factors such as tire size,amount of offset past the fender, tire tread type, and lift.

Think of it this way;

The tire moving past the fender creates turbulent air. The further outside of the fender, the worse it gets. If the tires are larger, they have more surface area, resulting in greater turbulence. Now if the vehicle is taller, that itself will affect aerodynamic drag, but it compounds with tire poke.

Tread type matters too. Highway tires with fairly smooth and complete tread have the lowest aerodynamic effect. Mud terrain tires with huge, deep tread blocks will have the greatest affect.

You kinda have to consider all of those factors to decide how much it's going to affect your situation. Someone with a 20mm offset and A/T's will not see the same loss in mileage as someone with 0 offset and mud-terrain's.

 

[Gator 22]

Excellent info, thanks. Having pizza cutters might not only give you better grip might be better milage too.

 

[NotApplicable]

Excellent info, thanks. Having pizza cutters might not only give you better grip might be better milage too.

Yeah, not only because of poke/air reactance, but also rolling resistance of wider segment width, but also the significantly increased weight of the giant tires a lot of people slap on

 

[Nodak]

also remember, new tires outside of the oem size/brand will most likely be heavier also. add in aftermarket wheels and the poke and you could be increasing more than just poke to the equation.

 

[Gator 22]

I'll probably pull the trigger on a 27 4Runner. This site has been giving me lots of info not only on features and mods but also lately info on longevity. It will be my 5th 4Runner and might be my last. I want to build a functional truck not one just for looks.

 

[Nodak]

just decide what your long term goals are. pavement princess, pavement princess with som mild off roading, or off road rig mostly with some pavement princess

i went full time pavement princess, done with the ruggedness and need the ft4wd for work and getting around town during the winters and the comfort to last as my retirement vehicle.

 

[Gator 22]

It will be a multi purpose 4Runner. Pavement but also a camping, (some places I like going are hard to get to even with 4x4) off road fun, light fire road fun, and fishing spots off the beaten path. I'm semi retiring in about 9 months. Live in S Fla. but have been hiking/climbing and fishing all over N America, especially Wyoming, Montana, Washing State and Colorado. I have "field tested" a lot of rental off road machines in these areas. Other than 4Runners Jeep Rubicon was the most capable but they suck in so many other ways its not even a choice.

 

[Joestac]

This is a reason why I think I've landed on the 265/70/18 Falken AT4W. They are a 33.4" diameter tire, so I am gaining some height over factory. Wish they had something a bit lighter than E load, but I'll just play with the tire pressure to gentle down the ride.

 

[Gator 22]

I think Good Year Ultra Terrains are offered in lower load rated models that are a lot lighter if your not rock crawling.

 

[Hey-Arnold]

just decide what your long term goals are. pavement princess, pavement princess with som mild off roading, or off road rig mostly with some pavement princess

i went full time pavement princess, done with the ruggedness and need the ft4wd for work and getting around town during the winters and the comfort to last as my retirement vehicle.

Pavement prioncess is what I am normally. i am from Chicago with very little off roading. more driving to and from work. i am thinking of getting up to michigan in the summers, maybe fall, to do some light off roading/rolling through some dunes, but nothing crazy. what tires/wheels do you have on yours?

 

[TRDLE]

I bought my ORP in August and swapped to heavy, bigger studded winter tires (285/70R17 Hakkapeliittas) and different wheels (offset 12) in October. They poked out quite a bit from the fender.
There was a small drop in mpg (from 17 to 15). I just switched back to factory wheels/tires this past weekend and immediately went from 15 to 18-19.
So yes, I’d say it makes a difference, but you also have to factor in the size and weight of your tires. I am also running winter fuel so all of that factors in.

 

[Nodak]

Pavement prioncess is what I am normally. i am from Chicago with very little off roading. more driving to and from work. i am thinking of getting up to michigan in the summers, maybe fall, to do some light off roading/rolling through some dunes, but nothing crazy. what tires/wheels do you have on yours?

defender ltx ms2 extra load in oem size for a platinum

 

[LostInAZ]

I have seriously stopped carrying about MPG on mine as I start adding more stuff and getting closer to GVWR. I started thinking more of it as SPG instead; Smiles per Gallons.

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