Ridiculous fuel mileage - no codes found - nothing Ford will do.
#22
Race Red '12 XLT SCrew EB
Stock tire diameter is 32". 34s are 2" bigger, increasing circumference by over 6". Added to the heavier weights, more aggressive tread and softer compounds. Lifting any vehicle will allow more air under to the most aerodynamically dirty area of a vehicle increasing drag at higher speeds, also decreasing fuel mileage.
It adds up quickly. anybody who thinks that doing this stuff won't effect mileage much should think again. Either return it to stock and drive 55 to get the window sticker mileage or live with what isn't unreasonable mileage considering the tires. Don't expect the milage to jump this time of year switching back to stock either. Most of us are down 2-3mpg because of winter fuel.
It adds up quickly. anybody who thinks that doing this stuff won't effect mileage much should think again. Either return it to stock and drive 55 to get the window sticker mileage or live with what isn't unreasonable mileage considering the tires. Don't expect the milage to jump this time of year switching back to stock either. Most of us are down 2-3mpg because of winter fuel.
#23
I called Ford and they told me that if I got the 20" aluminum on the Lariat I would see less mpg. width of these tires is part of it. not just height.
I cancelled my upgrade to 20's because I'm getting the ecoboost for mileage. still like the way the bigger tires look and may run them in summer but it really is a silly thing to do if you care about mileage.
the 20's ride rougher because of the lower profile tires and less mpg. looking cool can be really silly but we all are at times.
I cancelled my upgrade to 20's because I'm getting the ecoboost for mileage. still like the way the bigger tires look and may run them in summer but it really is a silly thing to do if you care about mileage.
the 20's ride rougher because of the lower profile tires and less mpg. looking cool can be really silly but we all are at times.
#24
Race Red '12 XLT SCrew EB
100.5" is stock circumference. 106.8" is your circumference. The stock wheels have to turn 630 time in a mile but the 34's will cover 1.06 miles in the same revolutions. That alone makes your indicated fuel mileage short by as much as 6%.
#25
Senior Member
I called Ford and they told me that if I got the 20" aluminum on the Lariat I would see less mpg. width of these tires is part of it. not just height.
I cancelled my upgrade to 20's because I'm getting the ecoboost for mileage. still like the way the bigger tires look and may run them in summer but it really is a silly thing to do if you care about mileage.
the 20's ride rougher because of the lower profile tires and less mpg. looking cool can be really silly but we all are at times.
I cancelled my upgrade to 20's because I'm getting the ecoboost for mileage. still like the way the bigger tires look and may run them in summer but it really is a silly thing to do if you care about mileage.
the 20's ride rougher because of the lower profile tires and less mpg. looking cool can be really silly but we all are at times.
Are they implying the 20's are a bigger tire in width and diameter? The weight of the 18's vs 20's might be off but I doubt the mileage would be much different. The 20' pirelli's are a fairly tame tire. I'd be inclined to believe the 20's would get better mileage.
#26
Heavier tire, lower mileage, usually. Tread pattern and stiffness play a role as well, but weight is the major culprit, I think.
#28
Senior Member
The 20" Pirelli's are about 42lbs per tire. The 18" BFG's are 43lbs and the Goodyears Wranglers are 49lbs per. (numbers off tirerack)
I agree weight and tread pattern make a difference but I can't see there being a noticible difference between the 18" and 20" stock options.
I've got the 20"s on mine, the average city and highway is somewhere between 13 and 14l/100km. If I take it easy (cruise at 120-125kph) on a road trip it's usually high 12's to low 13's.
I agree weight and tread pattern make a difference but I can't see there being a noticible difference between the 18" and 20" stock options.
I've got the 20"s on mine, the average city and highway is somewhere between 13 and 14l/100km. If I take it easy (cruise at 120-125kph) on a road trip it's usually high 12's to low 13's.
#29
Senior Member
I don't really see a problem. I have a CC 6.5' box ecoboost, 3.73 gears, stock everything, and in 6000 miles my average is 15.4 mpg. If you correct for the larger tires and then deduct because of the size, you are comparable.
I know the truck gets better mpg. Have you tried setting the cruise between 55-65 mph on a completely flat road in no wind? I can get 20-23 mpg at those speeds, in those conditions. Have gotten 18 mpg at 75 mph.
Are these the conditions I am always driving in...NO. That is why my truck shows 15.4 mpg average. When you mix in warming the truck up, driving short distances, cold tranny in the winter that takes a while to lock, hauling trailers, romping on it, thats what it gets. I know all of this comes into play, so it does not bother me.
For some reason I think a lot of peoples expectations were way too high for this engine. Plain and simple, this truck gets 20 mpg in the right conditions. Either you drive in these conditions and are thrilled with the mileage or you don't. Its not the trucks or manufacturers fault that you may not drive in the correct environment to achieve those numbers. Every vehicle out there is this way, not just the ECOBOOST.
If you set your cruise at 55 mph, perfectly flat with no wind and don't see around 20 mpgs(stock wheels and tires) than yes, you may have a problem. If you can achieve those numbers then the low mileage is purely driver habits and the environment it is being driven in.
I know the truck gets better mpg. Have you tried setting the cruise between 55-65 mph on a completely flat road in no wind? I can get 20-23 mpg at those speeds, in those conditions. Have gotten 18 mpg at 75 mph.
Are these the conditions I am always driving in...NO. That is why my truck shows 15.4 mpg average. When you mix in warming the truck up, driving short distances, cold tranny in the winter that takes a while to lock, hauling trailers, romping on it, thats what it gets. I know all of this comes into play, so it does not bother me.
For some reason I think a lot of peoples expectations were way too high for this engine. Plain and simple, this truck gets 20 mpg in the right conditions. Either you drive in these conditions and are thrilled with the mileage or you don't. Its not the trucks or manufacturers fault that you may not drive in the correct environment to achieve those numbers. Every vehicle out there is this way, not just the ECOBOOST.
If you set your cruise at 55 mph, perfectly flat with no wind and don't see around 20 mpgs(stock wheels and tires) than yes, you may have a problem. If you can achieve those numbers then the low mileage is purely driver habits and the environment it is being driven in.
#30
Race Red '12 XLT SCrew EB
The 20" Pirelli's are about 42lbs per tire. The 18" BFG's are 43lbs and the Goodyears Wranglers are 49lbs per. (numbers off tirerack)
I agree weight and tread pattern make a difference but I can't see there being a noticible difference between the 18" and 20" stock options.
I've got the 20"s on mine, the average city and highway is somewhere between 13 and 14l/100km. If I take it easy (cruise at 120-125kph) on a road trip it's usually high 12's to low 13's.
I agree weight and tread pattern make a difference but I can't see there being a noticible difference between the 18" and 20" stock options.
I've got the 20"s on mine, the average city and highway is somewhere between 13 and 14l/100km. If I take it easy (cruise at 120-125kph) on a road trip it's usually high 12's to low 13's.
https://www.f150forum.com/f38/18-20-...-weight-96715/
"20inch chrome clad wheels with 275/55-20 Scorpions weigh 80.5 lbs. 18inch chrome clad with 275/65-18 Michelin MS2 weigh 71 lbs. 9.5 lb per wheel weight savings with the 18 inch wheels."
12% lighter wheels and tires, giving a reduction of 38lbs. On another page posted in the above thread they claim a 1lb reduction of rotating mass equals a 10lb reduction of static weight.
This tells us that a truck with stock 20's thinks it is hauling around 380lbs more than the same truck with stock 18's even though the difference is only 38lbs.
Not to mention his 34's are not stock pirelli and weigh more.
***edit, pirelli scorpions weigh in at 48lbs, his tires are 57lbs. So another 360lbs for a total of 740lbs his truck thinks it is hauling around extra. This is assuming his 20" rims weigh the same as the 20" stock rims.
Last edited by EBinMT; 12-01-2011 at 06:14 PM.