MPG of performance tires - Ford Focus Forum, Ford Focus ST Forum, Ford Focus RS Forum
Ford Focus Forum
HomeContact UsAbout UsGalleryDiscussion ForumsMarketplace


Go Back   Ford Focus Forum, Ford Focus ST Forum, Ford Focus RS Forum > Ford Focus Tech Discussions > Wheels & Tires

Wheels & Tires The place to go for answers on wheel types, tire sizes, offset, wheel patterns and more.

Search This Forum | Image Search | Advanced Search    
FocusFanatics Merchandise

Reply
 
Thread Tools Display Modes
Old 05-24-2013, 11:49 PM   #1
metrognome
Focus Jr. Enthusiast
 
Join Date: Mar 2013
Fan#: 112081
Location: Milwaukie, OR
What I Drive: 2007 Silver ZX3 SE

Posts: 33
Points 298, Level 5
Points: 298, Level: 5 Points: 298, Level: 5 Points: 298, Level: 5
Level Up 96% Completed
Level up: 96% Level up: 96% Level up: 96%
Forum Activity 0%
Activity: 0% Activity: 0% Activity: 0%
FF Reputation: 5 metrognome Good Standing Member
Buy-Sell-Trade Rating: (0)
MPG of performance tires

Hi. noob here......

I was wondering how much difference there would be, in miles/gallon, running stock size P215/65R/15 and a 215/45R/17 ?

I'm driving an '07 2.0, 5spd, with cruise and NOT a lead foot haha.

Currently get 27-30mpg with the 17's that were on when I bought my Focus.
Would like to get at least mid 30's.

Could I get 5mpg more with a lower friction touring tire?

btw my Focus came into my possesion with a Steeda cai and a cat-back exhaust (that has a very mellow PURR at 70) already.
tia



Last edited by metrognome; 05-24-2013 at 11:54 PM. Reason: added a btw
metrognome is online now  
    Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
Old 05-25-2013, 12:27 AM   #2
zetecDon
Where am I?
 
zetecDon's Avatar
 
Join Date: Feb 2009
Fan#: 62506
Location: east of Cincinnati, OH
What I Drive: 02 ZX3, 02 MX-5

Posts: 8,239
Points 13,154, Level 74
Points: 13,154, Level: 74 Points: 13,154, Level: 74 Points: 13,154, Level: 74
Level Up 76% Completed
Level up: 76% Level up: 76% Level up: 76%
Forum Activity 37%
Activity: 37% Activity: 37% Activity: 37%
FF Reputation: 29 zetecDon Great Standing Member
Buy-Sell-Trade Rating: (46)
Moved to "Wheels, Tires, Brakes & Suspension" since your question is concerned about differences in tires.
zetecDon is online now  
    Reply With Quote Quick reply to this message
Old 05-25-2013, 12:49 AM   #3
Elizabeth
Focus Fanatic
 
Elizabeth's Avatar
 
Join Date: Aug 2011
Fan#: 89280
Location: SouthEast, WI
What I Drive: '14 Tangerine Scream ST3

Posts: 3,406
Points 14,754, Level 78
Points: 14,754, Level: 78 Points: 14,754, Level: 78 Points: 14,754, Level: 78
Level Up 76% Completed
Level up: 76% Level up: 76% Level up: 76%
Forum Activity 13%
Activity: 13% Activity: 13% Activity: 13%
FF Reputation: 16 Elizabeth Great Standing Member
Buy-Sell-Trade Rating: (0)
First off your replacement tire is way off size. The 215/65/15 is about 800 revolutions per mile. the 215/45/17 is way more revs per mile at around 844.
Your speedo will be crazy off.
If you go for 17" wheels to keep the speedo the same you would need 225/50/17

You want 5mpg more with just tires? crazy.
Well 5mpg more could be had with thin smooth wheels (which is just the opposite of what you are going with bigger wheels, mainy because bigger wheels are wider, and way harder to find skinny tires for..) , that is a wheel cover perfectly smooth either flat or dished, try the skinniest tires you can buy which have long tread full cuircumference with a reasonable on your smooth faced wheels.
Run those tires at 50psi...
Elizabeth is offline  
    Reply With Quote Quick reply to this message
Old 05-25-2013, 12:58 AM   #4
Indy'sexclusiveZx3
Focus Addict
 
Join Date: May 2009
Fan#: 65419
Location: Indianapolis, IN
What I Drive: 2013 tuxedo black st

Posts: 569
FF Reputation: 7 Indy'sexclusiveZx3 Good Standing Member
Buy-Sell-Trade Rating: (3)
I doubt he would be ever able to fit that size tire, I imagine you can get some low rolling restance tires, or by going to a 15" or 16" wheel and tire pacakage and get some unsprung mass off the car
__________________
Parts for sale check out my thread, got a new st need to sale old parts
Indy'sexclusiveZx3 is offline  
    Reply With Quote Quick reply to this message
Old 05-25-2013, 05:22 AM   #5
thenorm
Focus Fanatic
 
thenorm's Avatar
 
Join Date: Oct 2004
Fan#: 14947
Location: Vancouver, BC, Canada
What I Drive: '04 liquid grey ZX3, built for FSP

Posts: 2,131
Points 5,617, Level 48
Points: 5,617, Level: 48 Points: 5,617, Level: 48 Points: 5,617, Level: 48
Level Up 34% Completed
Level up: 34% Level up: 34% Level up: 34%
Forum Activity 4%
Activity: 4% Activity: 4% Activity: 4%
FF Reputation: 36 thenorm Great Standing Member
Buy-Sell-Trade Rating: (5)
you would see an increase with LRR tires. but i would only reasonably expect ~2mpg.

if efficiency really is your cause, i would go with a 185 wide tire (narrowest reasonable width) on an aluminum OEM 15x6 wheel.
__________________
May 2014 ROTM
for auto-x: '04 Liquid Grey ZX3
for street: '02 Infrared SVT
thenorm is online now  
    Reply With Quote Quick reply to this message
Old 05-25-2013, 02:13 PM   #6
Buickboy
br/o/stang
 
Buickboy's Avatar
 
Join Date: Oct 2005
Fan#: 28542
Location: Stratford, CT
What I Drive: 72 Skylark, '12 Mustang

Posts: 5,292
Points 28,322, Level 98
Points: 28,322, Level: 98 Points: 28,322, Level: 98 Points: 28,322, Level: 98
Level Up 98% Completed
Level up: 98% Level up: 98% Level up: 98%
Forum Activity 1%
Activity: 1% Activity: 1% Activity: 1%
FF Reputation: 39 Buickboy Great Standing Member
Buy-Sell-Trade Rating: (29)
your stock size is 195/60/15 on a 2007 foci
__________________
==2012 Kona Blue Mustang V6==
==1995 Light Iris Neon Coupe==
==1972 Skylark==
Buickboy is offline  
    Reply With Quote Quick reply to this message
Old 05-25-2013, 02:26 PM   #7
metrognome
Focus Jr. Enthusiast
 
Join Date: Mar 2013
Fan#: 112081
Location: Milwaukie, OR
What I Drive: 2007 Silver ZX3 SE

Posts: 33
Points 298, Level 5
Points: 298, Level: 5 Points: 298, Level: 5 Points: 298, Level: 5
Level Up 96% Completed
Level up: 96% Level up: 96% Level up: 96%
Forum Activity 0%
Activity: 0% Activity: 0% Activity: 0%
FF Reputation: 5 metrognome Good Standing Member
Buy-Sell-Trade Rating: (0)
Buickboy, I stand corrected. Thank you.
The question remains...( in spite of my miss quoting size)..could I get 5mpg more by switching to the 'stock' sizes?

thanks again

and btw, I do know about tire contact patch size and how it effects mileage but was seeking first hand knowledge from somebody who has changed from one to the other and actually measured the difference.
Real world experience numbers.
I do appreciate y'alls responses so far.

My curiosity arises from the desire to drive 1500 miles one way to visit my daughter and her family.
And what with gas prices being what they are, along with the extra carbon I would leave in my wake, would I truly benefit
5'ish mpg (or more) by changing from the wide 17's to a narrower 15?

btw, I DO like how the 17's feel on the twisties lol
If I could only realize 2-3 mpg I'll stick with the 17's

My last car was a 4 cyl, 5 spd, Suzuki Swift that got 39-42mpg depending on winter or summer gas.
Guess I got a little spoiled and by that 'sipper' and was expecting low to mid 30's from my newly purchased Focus.

I love her.
I just wish she didn't drink so much......
lol
metrognome is online now  
    Reply With Quote Quick reply to this message
Old 05-25-2013, 02:57 PM   #8
Joeywhat
Strichmädchen & Koks
 
Joeywhat's Avatar
 
Join Date: Apr 2011
Fan#: 85247
Location: Brighton, MI
What I Drive: 2014 Mustang 3.7L SGM

Posts: 2,973
Points 8,143, Level 60
Points: 8,143, Level: 60 Points: 8,143, Level: 60 Points: 8,143, Level: 60
Level Up 97% Completed
Level up: 97% Level up: 97% Level up: 97%
Forum Activity 8%
Activity: 8% Activity: 8% Activity: 8%
FF Reputation: 11 Joeywhat Great Standing Member
Buy-Sell-Trade Rating: (1)
Smaller diameter tires will negatively effect MPG, but I doubt you'd see 5 mpg increases going to the different size.

Expect another couple mpg out of it, especially if you get LRR tires.

It should also be noted that the money spent on new tires will NOT be recouped by fuel savings, you will be losing money. If you need tires anyways then great...if not, don't bother. You're just wasting money.
__________________
Hatch Nation #29
Joeywhat is offline  
    Reply With Quote Quick reply to this message
Old 05-25-2013, 06:49 PM   #9
dyn085
That Guy
 
dyn085's Avatar
 
Join Date: Apr 2012
Fan#: 98047
Location: Fayetteville, NC
What I Drive: 2014 FiST/FoST

Posts: 12,618
Points 26,132, Level 96
Points: 26,132, Level: 96 Points: 26,132, Level: 96 Points: 26,132, Level: 96
Level Up 79% Completed
Level up: 79% Level up: 79% Level up: 79%
Forum Activity 53%
Activity: 53% Activity: 53% Activity: 53%
FF Reputation: 50 dyn085 Excellent Standing Member
Buy-Sell-Trade Rating: (5)
I actually disagree. There can be a huge mpg gap strictly from OEM wheel/tire packages. Apples to Oranges here, but in the Mk3 community mileage from the 18's is usually 35-37 highway and those with 16's have seen 45+. Yes there's a million variables at stake, but the point is the same.

I'm under the assumption that you're considering an entire wheel/tire swap due to the different wheel measurements of your quoted tires. Something to consider-under the assumption that Buickboy is correct on the OEM sizing-is that you're already running an oversize tire and as such your mileage is probably currently incorrect by 1.65%.

Are the wheels that are on your car aftermarket? If so, chances are that they are comparatively light for their size. That isn't always true, but realistically it matters for mpg's and would need to be taken into consideration. It is most likely still heavier than the 15's, and the additional rotational mass and it's distance from the center of the axle isn't beneficial.

Joeywhat's final statement is pretty close to correct. If you're trying to get 5-8 mpg by purchasing new 15" wheels/tires, you're probably going to find the math more beneficial by keeping your current set on, unless you plan on running the car for more than one set of tires...
__________________
FocusFest 2013: Best of Show
Gateway FFW: Show Class Outstanding
September '13 ROTM
2014 FiST-
dyn085 is online now  
    Reply With Quote Quick reply to this message
Old 05-25-2013, 08:14 PM   #10
felixthecat
w/ my magic bag
 
felixthecat's Avatar
 
Join Date: Nov 2010
Fan#: 80663
Location: Renton, WA
What I Drive: '05 Silver Sport Technologies

Posts: 12,384
Points 13,747, Level 76
Points: 13,747, Level: 76 Points: 13,747, Level: 76 Points: 13,747, Level: 76
Level Up 25% Completed
Level up: 25% Level up: 25% Level up: 25%
Forum Activity 100%
Activity: 100% Activity: 100% Activity: 100%
FF Reputation: 67 felixthecat Excellent Standing Member
Buy-Sell-Trade Rating: (0)
That ^^^^^^^^^^plus, a Suzuki swift is a lighter car. The cost of wheels & tires & how long the pay back is. Just to add, the 17's would stop faster & manuver a lot better then the 15's. It could possibley save you from teepeeing your hood= a accedent.
__________________
Introduce Mr. Torsen to the mixBigger brakes then you- D23 crew- D-Tech- Sedan Revolution= #131
felixthecat is online now  
    Reply With Quote Quick reply to this message
Reply

Bookmarks & Social Networks

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Ford Focus Forum, Ford Focus ST Forum, Ford Focus RS Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Thread Tools
Display Modes

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -5. The time now is 10:50 PM.


Copyright 2002-2014 FocusFanatics.com. All Rights Reserved : Privacy Policy : Advertise Information

Focus Fanatics Ford Focus Forum offers many fun ways for you to engage with other Ford Focus Owners from across the world. Whether it be about the aftermarket performance modifications, technical how-to's, European tuned suspension or awesome fuel economy similar to the Audi S3, Ford Fusion and Acura TLX. You can find all Ford Focus and Focus ST related information here. Join our Ford Focus discussion forums and chat with local Focus enthusiasts in your area. Challenger Hellcat - Charger Hellcat