Tires
#21
07-21-2018, 01:10 PM
Veteran Member
Join Date: Dec 2017
Location: The Netherlands Central Highlands - Veluwe-
Posts: 1,236
Received 262 Likes
on
196 Posts
In winter, to avoid skidding, I would increase the ground pressure by using narrower winter tires. Altough with more and wider profile, you already get that with the same size/width . Best is to speak with forum members in your region,
as the car is around for some years and maybe someone uses its as a daily comuter..
#22
07-22-2018, 01:44 AM
Veteran Member
#23
07-22-2018, 06:56 AM
If you have OEM 295s on the rear then you have 255s on the front. If you don't have adapters or spacers on the car, you can safely go up 10mm both front and back. Some of us have upsized the rear only and others have upsized the front as well.
Here are actual diameters:
255/35-20 27.0" (OEM)
295/30-20 27.0" (OEM)
265/35-20 27.3"
305/30-20 27.2"
245/40-19 26.7" (OEM)
285/35-19 26.9" (OEM)
Upsizing by 10mm only increases the diameter by 1.1%. The speedometer will still read higher than actual. You will note that the 19" OEM tire size is a smaller diameter than the 20" tires by that same margin. No laws concerning tire size in the U.S. other than they cannot stick out beyond the fender. I can't wax poetic on handling improvement as I had upsized when I transitioned from the Pirellis. (stepwise improvement in handling).
Here are actual diameters:
255/35-20 27.0" (OEM)
295/30-20 27.0" (OEM)
265/35-20 27.3"
305/30-20 27.2"
245/40-19 26.7" (OEM)
285/35-19 26.9" (OEM)
Upsizing by 10mm only increases the diameter by 1.1%. The speedometer will still read higher than actual. You will note that the 19" OEM tire size is a smaller diameter than the 20" tires by that same margin. No laws concerning tire size in the U.S. other than they cannot stick out beyond the fender. I can't wax poetic on handling improvement as I had upsized when I transitioned from the Pirellis. (stepwise improvement in handling).
#24
07-22-2018, 08:01 AM
Veteran Member
No issues behind the rear wheels.
Last edited by Unhingd; 07-22-2018 at 08:04 AM.
#25
07-22-2018, 08:54 AM
If you have OEM 295s on the rear then you have 255s on the front. If you don't have adapters or spacers on the car, you can safely go up 10mm both front and back. Some of us have upsized the rear only and others have upsized the front as well.
Here are actual diameters:
255/35-20 27.0" (OEM)
295/30-20 27.0" (OEM)
265/35-20 27.3"
305/30-20 27.2"
245/40-19 26.7" (OEM)
285/35-19 26.9" (OEM)
Upsizing by 10mm only increases the diameter by 1.1%. The speedometer will still read higher than actual. You will note that the 19" OEM tire size is a smaller diameter than the 20" tires by that same margin. No laws concerning tire size in the U.S. other than they cannot stick out beyond the fender. I can't wax poetic on handling improvement as I had upsized when I transitioned from the Pirellis. (stepwise improvement in handling).
Here are actual diameters:
255/35-20 27.0" (OEM)
295/30-20 27.0" (OEM)
265/35-20 27.3"
305/30-20 27.2"
245/40-19 26.7" (OEM)
285/35-19 26.9" (OEM)
Upsizing by 10mm only increases the diameter by 1.1%. The speedometer will still read higher than actual. You will note that the 19" OEM tire size is a smaller diameter than the 20" tires by that same margin. No laws concerning tire size in the U.S. other than they cannot stick out beyond the fender. I can't wax poetic on handling improvement as I had upsized when I transitioned from the Pirellis. (stepwise improvement in handling).
#26
07-22-2018, 10:59 AM
Veteran Member
The tire size affects the odometer to the same extent as it does the speedometer. Install Waze in your phone and tell me how fast it indicates you are going when your speedometer is reading 60mph (or any other speed for that matter). Use cruise control to do this. I can then tell you what your speedometer error will be with the 305 tire. Based on my experience the indicated speed is now within 1mph on the high side at 60mph.
I chose not to go with the 265 on the front because I was uncertain whether that would work with my 15mm hub adapters.
I chose not to go with the 265 on the front because I was uncertain whether that would work with my 15mm hub adapters.
The following users liked this post:
Mbourne (07-22-2018)
#27
07-22-2018, 12:03 PM
Veteran Member
#28
07-22-2018, 06:20 PM
Veteran Member
Join Date: Feb 2014
Location: Adelaide, South Australia
Posts: 8,433
Received 3,209 Likes
on
2,366 Posts
Yep, as Lance says, going from 295s to 305s on the rear will cause your speedo to "under-read" by around 1 mph at 60 mph.
In other words, if your speedo says 60 mph you are really doing around 61 mph.
BUT, the F-Type speedo is around 5% optimistic at 60 mph anyway (5% over-read), so when your speedo says 60 mph you are only really doing around 57 mph.
So going to the 305s will correct this error just a little and your true speed will be closer to 58 mph.
Same effect with odometer.
In other words, if your speedo says 60 mph you are really doing around 61 mph.
BUT, the F-Type speedo is around 5% optimistic at 60 mph anyway (5% over-read), so when your speedo says 60 mph you are only really doing around 57 mph.
So going to the 305s will correct this error just a little and your true speed will be closer to 58 mph.
Same effect with odometer.
Last edited by OzXFR; 07-23-2018 at 02:49 AM.
The following users liked this post:
Mbourne (07-22-2018)
#29
07-22-2018, 09:12 PM
#30
07-22-2018, 11:13 PM
Veteran Member
Hey apropos tyre sizes, I have my F Type wheels coming off. The tyres are 245/40ZR19, and have heaps of meat still on them as I have just done 20,000km on them. Then my missus has her XE. The tyres are 225/40ZR19. Would I be able to use the F Type tyres on the XE when they need replacing?
#31
07-22-2018, 11:38 PM
Veteran Member
Join Date: Feb 2014
Location: Adelaide, South Australia
Posts: 8,433
Received 3,209 Likes
on
2,366 Posts
Hey apropos tyre sizes, I have my F Type wheels coming off. The tyres are 245/40ZR19, and have heaps of meat still on them as I have just done 20,000km on them. Then my missus has her XE. The tyres are 225/40ZR19. Would I be able to use the F Type tyres on the XE when they need replacing?
They would fill out the wheel well by an extra 8 mm and stick out an extra 10 mm, both of which would be in tolerance for an XE and probably make it look a helluva lot better.
But that is only one end, from memory the 19" tyres on the rear of your F-Type are a bit bigger, 275/35R19 I think, which if I am correct would be too big for the missus' XE.
So I reckon your F-Type front tyres would be OK on the rear of the missus' XE but that's about it.
The following users liked this post:
BruceTheQuail (07-23-2018)
#33
07-23-2018, 08:33 AM
Veteran Member
Hey apropos tyre sizes, I have my F Type wheels coming off. The tyres are 245/40ZR19, and have heaps of meat still on them as I have just done 20,000km on them. Then my missus has her XE. The tyres are 225/40ZR19. Would I be able to use the F Type tyres on the XE when they need replacing?
Last edited by Unhingd; 07-23-2018 at 08:39 AM.
The following users liked this post:
BruceTheQuail (07-23-2018)
#35
07-23-2018, 04:30 PM
Veteran Member
The F-type tires are about 3% larger (0.6-0.7" diameter) than the XE tires. Assuming this fits OK, it should introduce -3% error to your odometer/speedometer, i.e. you'd actually be going 3% faster than the speedometer indicates (not including the preexisting speedometer error.)
I think...
I think...
The following users liked this post:
BruceTheQuail (07-23-2018)
#36
07-23-2018, 05:49 PM
Veteran Member
Join Date: Feb 2014
Location: Adelaide, South Australia
Posts: 8,433
Received 3,209 Likes
on
2,366 Posts
Bruce, it is possible the F-Type wheels with tyres may not fit/work on the XE especially at the rear as I suspect the offsets (again especially the rear) are very different.
Easy enough to test though, just fit 'em and have a look!
The other option is to whip two wheels off the XE, one front and one back, read the offsets (printed/engraved/whatever on the inside) and compare them with the offsets of the F-Type wheels.
Easy enough to test though, just fit 'em and have a look!
The other option is to whip two wheels off the XE, one front and one back, read the offsets (printed/engraved/whatever on the inside) and compare them with the offsets of the F-Type wheels.
The following users liked this post:
BruceTheQuail (07-23-2018)
#37
07-23-2018, 06:02 PM
Veteran Member
Yeah, Also I wouldnt like to ruin the ride and handling in the XE which is really, really good. I am learning heaps, this is quite interesting.
Online it suggests that XE has offsets of 45 and 55 F & R respectively, the F Type is 49 and 27. So I guess that the big difference on the rears would be a problem, as you mentioned.
Online it suggests that XE has offsets of 45 and 55 F & R respectively, the F Type is 49 and 27. So I guess that the big difference on the rears would be a problem, as you mentioned.
#38
07-23-2018, 06:07 PM
Veteran Member
Join Date: Feb 2014
Location: Adelaide, South Australia
Posts: 8,433
Received 3,209 Likes
on
2,366 Posts
Thread
Thread Starter
Forum
Replies
Last Post
maxthrottle
Wheels / Tires, Suspension & handling
13
07-05-2021 02:24 AM
CCJagtyper
PRIVATE For Sale / Trade or Buy Classifieds
0
09-26-2011 10:05 PM
jeiiomix
PRIVATE For Sale / Trade or Buy Classifieds
0
02-03-2010 11:49 PM
Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)