20 " Pirelli tires
Junior Member
Joined: Sep 2010
Posts: 1
Likes: 0
From: Springfield, IL
Im interested in the answer to this question, can the spedometer be adjusted to acurately compensate for the larger diameter tire?
Senior Member
Joined: Sep 2009
Posts: 3,031
Likes: 45
From: The Shenandoah Valley
This is not true unless you want to get into picking fly dung out of pepper and match non-stock tire sizes not available through the vehicle manufacturer to the wheels available through the manufacturer. I've been down this road before, and stock/optional available 20" wheel combinations characteristically are heavier and provide greater rolling resistance than the standard available 17" or 18" wheel combinations. That alone creates more drag and more mass to get rolling, which in turn eats away at out of the hole performance and fuel economy when compared to the smaller standard available "less than 20" wheel" counterpart.
My dad and I have been driving comparable trucks as far as engine, rear end, trim, etc., but I always used to get 20" wheels. There was a definite differnce in long-range fuel economy, around town driving economy (stop and go), as well as out of the hole performance. That is the main reason I went with 18" wheels with my current 2010 as I tow a large travel trailer and wanted all the grunt and mileage I could get - especially after enduring 20" wheels and tire on my last 2008 wasn't so great.
My dad and I have been driving comparable trucks as far as engine, rear end, trim, etc., but I always used to get 20" wheels. There was a definite differnce in long-range fuel economy, around town driving economy (stop and go), as well as out of the hole performance. That is the main reason I went with 18" wheels with my current 2010 as I tow a large travel trailer and wanted all the grunt and mileage I could get - especially after enduring 20" wheels and tire on my last 2008 wasn't so great.
Unless you compare figures with the 18 vs 20 wheel tire combo on the same truck making the same trip with same driver and load though, can't buy the mileage deal. I can't see the 20" as offering more rolling resistance either, certainly not using the same tire construction.
Why would it? Same tire construction with lower sidewalls would actually be less resistive to rolling favoring the 55 series on a 20" wheel.
Weight? Looking at TireRack, the Perelli is shown at 47 pounds for the 275/65-18 and 42 pounds for the 275/55-20 .... wonder if the 20" factory alloy is really more than 5 pounds heavier than the factory 18" alloy .... which it would have to be to make your case I think.
As to ride, same truck, same suspension tuning, yes .... I can see where the 18 might be some softer riding ... it should with taller sidewalls and lower pressures .... but Ford uses different shocks for them. The Perelli at only 35 psi is squirmy, wanders, is "soft" by my ideas.
Compare the OE 18" tire, a 275/65-18 BFG Rugged Trail T/A and it's 2601 pound rating at only 35 psi versus the OE Perelli Scorpion 275/55-20 at 2403 pounds at 44 psi and it's easy to see why the 20" rimmed trucks have a slightly (500 lbs I think) lower GVWR. This BFG tire weighs 43 pounds, so overall weight of tire and wheel is much closer as well (as I don't believe there's really 5 pounds difference between the 18 and 20" alloy wheels).
Tire costs for the 275/65-18 BFG today at TireRack is $704 a set or $176 ea. The 275/55-20 Perelli Scorpion is $660 a set or $165 each. I checked for 2007 (mine) and 2010 (your's) both.
Maybe you just had a heavier foot than Papa?
Junior Member
Joined: Mar 2012
Posts: 2
Likes: 0
2011 F150 Lariat Supercrew 4x2 - Pirelli (275/55/20).
Want to replace with - Bridgestone Dueler Rev 2 (275/60/55).
Because of larger sidewall (larger diameter tire), will I encounter any problems,
ie rubbing, speedo, etc?
Want to replace with - Bridgestone Dueler Rev 2 (275/60/55).
Because of larger sidewall (larger diameter tire), will I encounter any problems,
ie rubbing, speedo, etc?
Junior Member
Joined: Mar 2012
Posts: 2
Likes: 0
2011 F150 4x2 Lariat
2011 F150 4x2 Lariat Supercrew
Have - Pirelli 275/55/20 (stock)
Want - Bridgestone Revo 2 275/60/20
Will larger sidewall (larger diameter tire) be a problem, ie.
rubbing, speedo error, etc., or any other problems?
Have - Pirelli 275/55/20 (stock)
Want - Bridgestone Revo 2 275/60/20
Will larger sidewall (larger diameter tire) be a problem, ie.
rubbing, speedo error, etc., or any other problems?
Senior Member
Joined: Jan 2011
Posts: 610
Likes: 0
From: Fairbanks, AK
I agree that the same tire (ie: Perelli) in a 275/65-18 size at the same 44 psi carries a higher 2760 pound load rating than it does in the 275/55-20 size at 2403 pounds .... and it's because the 18" size being roughly the same overall diameter and width but with a smaller rim has a larger interior volume, so more air, more interior surface, more square inches of air pressing at 44 psi above atmosphere to carry that weight.
Unless you compare figures with the 18 vs 20 wheel tire combo on the same truck making the same trip with same driver and load though, can't buy the mileage deal. I can't see the 20" as offering more rolling resistance either, certainly not using the same tire construction.
Why would it? Same tire construction with lower sidewalls would actually be less resistive to rolling favoring the 55 series on a 20" wheel.
Weight? Looking at TireRack, the Perelli is shown at 47 pounds for the 275/65-18 and 42 pounds for the 275/55-20 .... wonder if the 20" factory alloy is really more than 5 pounds heavier than the factory 18" alloy .... which it would have to be to make your case I think.
As to ride, same truck, same suspension tuning, yes .... I can see where the 18 might be some softer riding ... it should with taller sidewalls and lower pressures .... but Ford uses different shocks for them. The Perelli at only 35 psi is squirmy, wanders, is "soft" by my ideas.
Compare the OE 18" tire, a 275/65-18 BFG Rugged Trail T/A and it's 2601 pound rating at only 35 psi versus the OE Perelli Scorpion 275/55-20 at 2403 pounds at 44 psi and it's easy to see why the 20" rimmed trucks have a slightly (500 lbs I think) lower GVWR. This BFG tire weighs 43 pounds, so overall weight of tire and wheel is much closer as well (as I don't believe there's really 5 pounds difference between the 18 and 20" alloy wheels).
Tire costs for the 275/65-18 BFG today at TireRack is $704 a set or $176 ea. The 275/55-20 Perelli Scorpion is $660 a set or $165 each. I checked for 2007 (mine) and 2010 (your's) both.
Maybe you just had a heavier foot than Papa?
Unless you compare figures with the 18 vs 20 wheel tire combo on the same truck making the same trip with same driver and load though, can't buy the mileage deal. I can't see the 20" as offering more rolling resistance either, certainly not using the same tire construction.
Why would it? Same tire construction with lower sidewalls would actually be less resistive to rolling favoring the 55 series on a 20" wheel.
Weight? Looking at TireRack, the Perelli is shown at 47 pounds for the 275/65-18 and 42 pounds for the 275/55-20 .... wonder if the 20" factory alloy is really more than 5 pounds heavier than the factory 18" alloy .... which it would have to be to make your case I think.
As to ride, same truck, same suspension tuning, yes .... I can see where the 18 might be some softer riding ... it should with taller sidewalls and lower pressures .... but Ford uses different shocks for them. The Perelli at only 35 psi is squirmy, wanders, is "soft" by my ideas.
Compare the OE 18" tire, a 275/65-18 BFG Rugged Trail T/A and it's 2601 pound rating at only 35 psi versus the OE Perelli Scorpion 275/55-20 at 2403 pounds at 44 psi and it's easy to see why the 20" rimmed trucks have a slightly (500 lbs I think) lower GVWR. This BFG tire weighs 43 pounds, so overall weight of tire and wheel is much closer as well (as I don't believe there's really 5 pounds difference between the 18 and 20" alloy wheels).
Tire costs for the 275/65-18 BFG today at TireRack is $704 a set or $176 ea. The 275/55-20 Perelli Scorpion is $660 a set or $165 each. I checked for 2007 (mine) and 2010 (your's) both.
Maybe you just had a heavier foot than Papa?
For the F150 with the chrome wheel packages, the weight of the goodyear tire is 39lbs each for the 18" rim, as compared to 48lbs for the pirelli on the 20" wheel. On top of that, the 18" wheel itself weighs 29lbs and the 20" wheel weighs 32.5lbs. This means the total weight for these wheels would be 68lbs for the 18" and 80.5lbs for the 20". 12 and a half pounds is a huge difference in weight per wheel/tire, and could definitely lead to improved fuel economy and responsiveness on the smaller wheel.
Last edited by Gerrard155; Mar 28, 2012 at 03:56 AM.
