how low on 18s

tubby-ben

Registered User
hi guys hope your all ok
finally done my 1st mod last night and fitted a set of 18 inch alloys with 225/40/18 tyres....
1st thing is how low can i drop her without rubbing and having to do the front arb mod?
2nd thing is how inaccurate is my speedo now? have been told by someone if my speedo is saying 50mph then im doing 43mph?
hope someone can shed some light. cheers.......
 

jojo

Looking for Boost!
Staff member
Moderator

Can't answer your question mate as I have an S3, but give it a chance man. It's Easter weekend, not everyone is lurking on the forums this weekend....
 

nealb

Registered User
hey bro im in the same boat man but got 215 40 18's use the tyre stretch calculator you need to down load it and it will tell you what the new speed difference will be hope that helps and if you go to low I have heard the sumps can take a beating but you can get shallow sumps to connvert too but im thinking maybe 30-40mm
 

TDIQ

8L > 8P > 8V
hey bro im in the same boat man but got 215 40 18's use the tyre stretch calculator you need to down load it and it will tell you what the new speed difference will be hope that helps and if you go to low I have heard the sumps can take a beating but you can get shallow sumps to connvert too but im thinking maybe 30-40mm
The sumps cannot take a beating. They are quite fragile.

If you want to check your speed get a sat-nav and use it to compare your speed to the clocks...
 

VAG-Slag

Registered User
2nd thing is how inaccurate is my speedo now?

The rolling radius of a 225/40/18 is pretty much exactly the same as the standard 16 inch sport rim so there should be little to no inaccuracy in your speedo and to be fair they're not exactly 100% accurate anyway. . . i wouldn't worry about it mate
 

tubby-ben

Registered User
The rolling radius of a 225/40/18 is pretty much exactly the same as the standard 16 inch sport rim so there should be little to no inaccuracy in your speedo and to be fair they're not exactly 100% accurate anyway. . . i wouldn't worry about it mate
cheers mate, have followed my mates car at 30 mph, 40, 50 and 60 and seems about 2-3mph out so basically at 60mph im doing roughly 57-58 mph. just didnt wanna get zapped by a camera as there is 1 around my way that gives you no mercy, 31 in a 30 and bang it goes off. cheers.......
 

rayh77

S3 AMK Merlin Purple
Look under the car, check out at what angle the dog legs are at now, (as dont know what suspension your on) you can lower them to your choice, but in my opinion ya can lower them to the point they are flat,.horizontal, as soon as they start pointing upwards (from car to ball joint) you start losing ya suspension, i.e., losing suspension travel, dropped mine 25 front, 20 rear.. running 18s she's holds well. I learnt this from seriously experienced chap, who knows what he's taking about, Dropped a Valver too low once, literally tore the bulk head open... as was practically running on bump stops..
 
Top