Will 285/75/16 noticably decrease fuel efficiency?
Junior User
Joined: Sep 2005
Posts: 70
Likes: 0
I just upgraded from 265 to 285/75/16 Michelin LTX M/S2 last week and had many of the same concerns. What I have found is that with the 265 tires, my speedometer was off by 2 - 3 mph. So with a speedometer reading of 65, I was really only going 62. With the 265 tires you're actually overstating your actual mileage simply because of the speedometer error. I was on the freeway yesterday and with my son's geocaching GPS phone app running. It reads to the nearest 100th of a mph and with my speed set to exactly 65mph, the GPS was reading exactly 65.00mph!
As an aside, the new Michelin LTX M/S2's are the quietest tires I have ever driven down the highway! I should note my tire experience goes all the way back to learning to drive on a then new 1964 Chevy Carryall Suburban. If you're looking for a quiet and smooth ride, I highly recommend these tires. I should also add that Ford currently has a $60 rebate if you buy 4 tires at the dealer, plus Michelin has a $70 rebate on 4 new tires. Not bad!
As an aside, the new Michelin LTX M/S2's are the quietest tires I have ever driven down the highway! I should note my tire experience goes all the way back to learning to drive on a then new 1964 Chevy Carryall Suburban. If you're looking for a quiet and smooth ride, I highly recommend these tires. I should also add that Ford currently has a $60 rebate if you buy 4 tires at the dealer, plus Michelin has a $70 rebate on 4 new tires. Not bad!
Cargo Master
Joined: Oct 2006
Posts: 2,097
Likes: 5
From: chicago northwest suburbs
I just upgraded from 265 to 285/75/16 Michelin LTX M/S2 last week and had many of the same concerns. What I have found is that with the 265 tires, my speedometer was off by 2 - 3 mph. So with a speedometer reading of 65, I was really only going 62. With the 265 tires you're actually overstating your actual mileage simply because of the speedometer error. I was on the freeway yesterday and with my son's geocaching GPS phone app running. It reads to the nearest 100th of a mph and with my speed set to exactly 65mph, the GPS was reading exactly 65.00mph!
Lead Driver
Joined: Oct 2010
Posts: 5,420
Likes: 16
From: Ouray, CO
I see the same thing - sort of.
I've got 265/75 Mich LTX M/S on my 2wd.
I see the speedometer 2-3 miles "low" compared to GPS @ 70 also.
BUT, my OBDII reads the SAME as my GPS.
So, the speedometer is wrong, but the computer correct?
Thus, when you put on 285 tires, the ODBII (computer?) is now
"wrong" but speedometer correct?
On my next highway drive, I want to use the GPS to track the "distance"
traveled and compare that to both the trip meter & ODBII
computed distance.
Maybe Ford "set" the computer for the 265 tire size, but couldn't
change the dashboard speedometer from the 285 calibration?
I've got 265/75 Mich LTX M/S on my 2wd.
I see the speedometer 2-3 miles "low" compared to GPS @ 70 also.
BUT, my OBDII reads the SAME as my GPS.
So, the speedometer is wrong, but the computer correct?
Thus, when you put on 285 tires, the ODBII (computer?) is now
"wrong" but speedometer correct?
On my next highway drive, I want to use the GPS to track the "distance"
traveled and compare that to both the trip meter & ODBII
computed distance.
Maybe Ford "set" the computer for the 265 tire size, but couldn't
change the dashboard speedometer from the 285 calibration?
New User
Joined: Oct 2015
Posts: 3
Likes: 0
I just upgraded from 265 to 285/75/16 Michelin LTX M/S2 last week and had many of the same concerns. What I have found is that with the 265 tires, my speedometer was off by 2 - 3 mph. So with a speedometer reading of 65, I was really only going 62. With the 265 tires you're actually overstating your actual mileage simply because of the speedometer error. I was on the freeway yesterday and with my son's geocaching GPS phone app running. It reads to the nearest 100th of a mph and with my speed set to exactly 65mph, the GPS was reading exactly 65.00mph!
As an aside, the new Michelin LTX M/S2's are the quietest tires I have ever driven down the highway! I should note my tire experience goes all the way back to learning to drive on a then new 1964 Chevy Carryall Suburban. If you're looking for a quiet and smooth ride, I highly recommend these tires. I should also add that Ford currently has a $60 rebate if you buy 4 tires at the dealer, plus Michelin has a $70 rebate on 4 new tires. Not bad!
As an aside, the new Michelin LTX M/S2's are the quietest tires I have ever driven down the highway! I should note my tire experience goes all the way back to learning to drive on a then new 1964 Chevy Carryall Suburban. If you're looking for a quiet and smooth ride, I highly recommend these tires. I should also add that Ford currently has a $60 rebate if you buy 4 tires at the dealer, plus Michelin has a $70 rebate on 4 new tires. Not bad!
Moderator
Joined: Jul 2010
Posts: 12,050
Likes: 1,549
From: Media PA
Welcome to the EX forum!
If you are still running the stock EX rims the 285 tires will fit fine with no spring rub.
Wiser by FTE
Joined: Jan 2010
Posts: 2,837
Likes: 48
The error will be only 3.7%. At 2000 RPM, you will be going approximately 72.6 mph in fifth gear. Conversely, at 70 mph, you will only be turning about 1925 RPM instead of 2000 RPM.
This is not too bad. You may see some slight decrease in mileage. Biggest issue will be if you tow a large aerodynamic drag (like a travel trailer). May be hard to get in the "prime" zone of 2000 RPM.
My experience is that speedo already reads high by about 3%. So...yours may actually now read correct speed for a given RPM.
This is not too bad. You may see some slight decrease in mileage. Biggest issue will be if you tow a large aerodynamic drag (like a travel trailer). May be hard to get in the "prime" zone of 2000 RPM.
My experience is that speedo already reads high by about 3%. So...yours may actually now read correct speed for a given RPM.
Logistics Pro
Joined: Jan 2014
Posts: 3,595
Likes: 17
Scanned this quickly, surprised nobody mentioned fuel consumption will decrease on the freeway. Larger tires will cause a lower cruising RPM if stock gears are retained. Granted 285/75's aren't much bigger than stock compared to my 35's. Both Razzi and I have noticed a small gain in MPG with larger tires.
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)
Brett Foote
Top 10 Ford Truck Tragedies
Joe Kucinski
AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make
Brett Foote
Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!
Michael S. Palmer
Ford's 2001 Explorer Sportsman Concept Looks For a New Home
Verdad Gallardo
10 Best Ford Truck Engines We Miss the Most!
Joe Kucinski
2026 Shelby F-150 Off-Road: Better Than a Raptor R?
Brett Foote
2027 Super Duty Carhartt Package First Look: 12 Things You NEED to Know!
Michael S. Palmer
10 Most Surprising 2026 Ford Truck Features!
Joe Kucinski
FTE Leadership Emeritus
Joined: Sep 2003
Posts: 12,246
Likes: 761
From: Houston, Texas
Will 285/75/16 noticably decrease fuel efficiency?
Scanned this quickly, surprised nobody mentioned fuel consumption will decrease on the freeway. Larger tires will cause a lower cruising RPM if stock gears are retained. Granted 285/75's aren't much bigger than stock compared to my 35's. Both Razzi and I have noticed a small gain in MPG with larger tires.
When I first met Matt, I used the ae to recalibrate his speedo for his 35s.
If you own a 6.0, you'll have to do the same to get the pcm and GPS to agree.
If you're tuned and are running factory mags, set the revs per mile to 615 for 285s and 305s. (Same size just different widths 70 vs 75) after first setting the pcm to the proper tire size.
Lead Driver
Joined: Mar 2010
Posts: 5,250
Likes: 10
From: West Virginia
I went from stock Michelin to 285 75 16 all terrains and they rubbed at full lock so I did front v codes and that cured it. Fuel mileage dropped about 2-3 mpg from just the tires. I was surprised. I have gained maybe half that back when I went to the falken wild peak ht's which are highway tread. I do too much highway driving I can't stand the way the at's all end up vibrating after 10k miles on the truck, but I like the slightly larger size. Looks better, drops. My cruising rpm a tad, and makes my speedo dead on accurate.
Senior User
Joined: Aug 2006
Posts: 307
Likes: 0
From: Siesta Key, FL
Ran Michelin LTX 285's for close to 70k miles and never rubbed. Just replaced them with Cooper's and they don't rub either. I never saw a mileage change when I stepped up to the 285's and made the adjustments to my tune with my Livewire.
Tuned
Joined: Aug 2004
Posts: 449
Likes: 0
From: North Texas
I have never ever, gotten better than 16 on the highway in my 7.3. What else have you done to the rig & how heavy (or not) is your foot on the highway?
Tuned
Joined: Aug 2004
Posts: 449
Likes: 0
From: North Texas
I have never ever, gotten better than 16 on the highway in my 7.3. What else have you done to the rig & how heavy (or not) is your foot on the highway?
please forgive me, I know its an old thread, but...
please forgive me, I know its an old thread, but...
New User
Joined: Oct 2015
Posts: 3
Likes: 0
I just mad the jump today from 265 75r 16 to Cooper discovery AT 3 285 75r16 and they don't rub at all in fact they look so better and fill in the wheel well I all so got an alignment so if you are rubbing check you toe adjustment as for the mpg I use to get 9-11 mpg city and 15-17 highway if I see a change I'll post it
Thread
Thread Starter
Forum
Replies
Last Post
whateverittakes
1999 - 2003 7.3L Power Stroke Diesel
5
Feb 11, 2016 02:15 AM
varminthunter243
1999 - 2016 Super Duty
17
Feb 7, 2016 03:04 PM
