What is offset?


One of the most asked questions, what's the offset closely followed by what is the biggest wheel that can I fit onto my car? The offset is a gauge of how much a wheel will stick out from the arch of a car or how far it will recess into the arch of the car. If the offset is wrong, the wheels will stick out too far and will almost be a like a beach buggy!

If you take a wheel and cut it in half and draw a line down the centre of the width of a wheel (Figure 1), the offset would be the distance between the back face (mounting face) of the wheel and the centre line that you have just drawn (shown as a dotted line in Figure 1).


Figure 1

It is very important not to deviate too far from the offset of the wheel originally fitted to the vehicle. A wheel of radically different offset can cause serious clearance and handling problems along with accelerated tire and bearing wear.

The offset is commonly shown as a et number, i.e.et49. This means the offset is 49mm. The offset is always measured in millimeters and can normally be found at the back of the wheel or stamped behind the center cap (if fitted).

Negative scrub geometry had the intention that if you got a flat tire you were still able to control the car (so long as you weren't going motorway speeds). So its best to keep as close to the OEM offset as possible.

However the bigger the alloy wheel goes, the more difficult it becomes to stay close to the oem offset. The reason being is that as wheel gets bigger in diameter, it also becomes wider, and so does the tyre that fits it. This is when other items in the wheel arch can begin to foul with the alloy wheel or the tire. Namely the arch lip of the car and the suspension strut (Figure 2). When this happens the offset must change for the bigger wheel and tyre to fit in the arch. Plus if the car has been lowered, this will have to be considered too as the wheel is now tucked further up in the arch.


Figure 2

 

What is the OEM 17" wheels offset?

 

Nice post, cTLgo. I think this is probably Garage-worthy and I'll try to add it.

Edit: Or you could add it to your sticky at the top of the page.

 

Excellent Post - sticky this bad boy. And 6mtV6, the offset for the stock 17 is 45.

 

Rets has added it to the garage, it will be added to the Tires/Wheels/Suspension portion of the garage and the sticky above once rets does some tweaking. Thanks

 

Has anyone done measurements inside the TL wheel well to determine the maximum width wheel, tire, and offset combination??

I need to confirm that a 20x9 with a 45-50 offset on a 245 wide tire will work.

I know a lot of people talk about 19x8.5 45 offset as a sure thing but I need to know about this size.

 

you can find that information in the first few posts here:

https://acurazine.com/forums/showthread.php?t=63320

you can go with a 20x9 wheel, offset will depend on wheel design and if you have 5AT or 6MT. 245 might be not wide enough for a 9" wheel, might want to go up to 255. There are a few members on the site with 20s, you might want to check there specs.

https://acurazine.com/forums/showthread.php?t=15225
https://acurazine.com/forums/showthread.php?t=109712

 

MY biggest problem in fitting wheels to my 6MT car was not size or offset (although I do agree this has a huge effect on rubbing etc), but rather the dimentions on the back side of the wheel. Some wheels have thicker spokes or in actuality, wrap around back the wheel in the direction of the mounting plate faster than others. This means that the BACK OF THE WHEEL won't clear the LARGER Brembo calipers no matter what offset your using. It really becomes an exercise in trial and error if the manufacture has not ever tried a specific car/wheel application.

For me, Foose said the Speedster 5's in a 45 offset would fit in a 18" wheel. When they didn't fit, they said try the 34 offset. It didn't fit either, so I tried the larger 19" wheels thinking that the spokes would not wrap in as quickly on their way to the outside of the rim....no luck. At that point Foose said to go with spacers and I declined their invitation because I wanted a low vibration hubcentric fit and went with a different wheel that fit fine with the same size and offset.

I wish there was a universal answer....but my experience would indicate that there is not.

 

What about staggared setups..? I understand going with an 8.5 +35 up front due to the Brembos but what about the rear... wouldn't that be a lower offset with so much less caliper to space for?

I was wondering if anyone is running either staggared offsets on same width i.e. 18x8.5 +35 front / 18x8.5 +25 rear or fully staggared setups such as 8.5 front 9.5 rear...?

I am looking at two different Work wheels and these are the offsets that look to me like they would fit... does anyone know for sure?

19x8.5 +40 R - Disk (front)
19x9.5 +42 O - Disk (rear)

or

19x8.5 +39 R - Disk
19x9.5 +44 O/A - Disk

 

King Leo: The R disk for the fronts should be OK be it 40 or 39 offset if you run 245/35 tires. 235/35 will give you a smidge more clearance.

The rear might be OK or rub lightly with 42 or 44 offset and 9.5" wide, especially if you have bodykit.

If I were you, I'd get something of the same width but different offset to give you the staggered look but without worse understeer. I also think that the lowest offset for 8.5" is 30 mm for the rear.

Once again, it's all based on my experience wheel-shopping for the car and my calculations. Also different tires of the same size will have different actual sizes. Keep this in mind.

 

Why would you want more witdh in the rear on a fwd car?

why dont you try same witdh with different offsets.

 

Thx 260!
That's exactly what I needed to find out.
~Leo

Nandito28,

I am looking for that staggared look.. but didn't want to run different widths for aparent FWD issues, i.e. heavy understeer.

I think the best setup would be 19x8.5 with +40 front and +30 rear.
It would look stagarred and not cause to much understeer.
~Leo

 

Yeah, I personally dont like the staggered look. But I had to go with it since I have the brembo breaks up front. I wish I had the regular breaks up in the front although the Brembos are nice!!! they've been nothing but a headache to me in choosing rims for it and all the squeaking they create for me!!!

BTW, I dont know my offsets. Sorry

All I know the lip in the front is going to 1.5' and the rear is going to be 2.5" from what I was told that was the max they could get.

I would of loved to do 2.5 all around!

 

That's a hott setup though... 1.5 front and 2.5 rear...
That's the setup I currently have on my S2000.

So 2.5 is the most that can be dished on a 3G TL... Not bad for a FWD car

 

Can you take pics of the front wheel with the 1.5'

I haven't gotten the wheels yet and I have no clue how the 1.5' lip will look...other than a tape measure...I'll PM you my email.

Thanks

 

Nandito

1) You could've gotten 1.5" all around if you wanted to avoid the staggered look.

2) Pics of 1.5"/2.5":

cTLgo's car

https://acurazine.com/forums/showthr...=smoked+ronjon

Pics 24-33

http://www.ronjonwheels.com/hidden/i...nprogresspics/

 

^^^^
Wow now that is a clean setup!!!
What are the widths and offset for that setup???

 

Yeah I know, but I love the deep look to much! At least now (later) I can see them from the back.

 

Leo - RonJon 3pc Devotions, 19X8.5, et37 all around for AT, 43.5 F/37 R for MT. Check out www.ronjonwheels.com

Nandito - lol...I know what you mean...I'd love a BBK, but not worth giving up that 2.5 all around...I love it!

 

Chill_dog,

Wow I didn't know Ron was working on cars straight off the Trailer (new) with the wrapping still on them...that was like three new cars!

Thanks for the pics...I really wanted to see (from an angle) how the 1.5' lip looked...How come he doesn't have this on his site...would be helpful IMO, But than again I never asked him if he had more pics.

Thanks!

 

Those pics were originally posted in the Group Buy thread waaaay back. The thread's long gone and you can't search the Black Market to find archived threads.

 

I like my staggered setup

 

I like the sound of that!
as far as the 19x8.5 43.5 offset for the fronts...
how pushed out is that, is the same setup as the pics listed above?

what I was looking for was a width and offset the pushes the wheel as close to the edge of the fender as possible without sticking out. Something as aggressive as the concept A-Spec offset.

BTW.. the RJ wheels are insanely gorgeous

 

Yeah, that's what's in the pics I linked (both cTLgo's and the AM at the dealer).

Ron makes some great looking wheels...top notch quality...excellent customer service. I know I sound like a commercial, but that was my (and many other member's) experience. I also like his new 1pF's...a set of 20's that weigh just shy of 20 lbs! I have to admit, it's tempting.

 

me too! im not going to buy what others like.. but what I think looks great.

 

Just purchased some 19x8.5's and 19x9.5's with a 38mm offset all around!!!! Does any one know if this will be okay??? I am also looking for tires at the moment...any tire size recommendations for this staggered set up to prevent rubbing issues? My car sits at stock height. Thanks!

 

i got my eye on these 18 inch 7.5'' wheels, and i wanna stay with 235/40/18, what offset would i need to fit it nice like the oem wheels? can i fit 235 on the car with a narrower mag?

thanks

 

Opinions needed for 18x8 with offset of +50. Will that look funnie or should i get some spacers with it?

 

what would be the offset for 22 x 8.5 rims? and tire size? on a 06 TL automatic

 

19x8 5x114 30gmm

19x8 5x114 42gmm

19x8 5x114 48gmm

Which of the above offset sizes will offer the deepest lip?

 

okay i think i found the answer to that question. now does anyone know if 30mm will work with a TL?

 

 

ok so this thread is ancient but i will give it a shot looking for some help
i cant understaand the offset terminology.
the tl has a stock wheel offset of 40 i believe correct me if im wrong
so does a lower offset bring the wheel further away from the face of the wheel or closer.
in other words does a higher offset make the wheel bulge out of the fenders or the opposite? please im looking att some wheels but the offset is crazzy here it goes i want to see if i can fit 10's in the rear..

F: 19x9 +36 O-disc /
R: 19x10 +23 O-disc

 

Lower offset moves the wheel out. Stock is 45mm. You can use this calculator to check what changing the offset will do http://www.1010tires.com/WheelOffsetCalculator.asp

According to the calculator, that rear wheel would move out almost 2", so over an inch of the wheel would stick out of the fenderwell.

 

thanks for the link

 

FlyDog's link above is pretty good but I think this one gives a better visual indication and gives you an estimate on suspension and fender clearances:

http://www.rims-n-tires.com/rt_specs.jsp

 

The problem with this theory is if you buy a 1 piece wheel. With a 1 piece changing offset doesn't change the lip size.

 

That link is pretty cool, but it doesn't properly calculate how much the wheel face comes out.

I entered 235/45-17 on the stock 8" wheel and 235/40/18 on an 8.5" wheel. That works out to 16mm (10mm increase in offset + half the increase in wheel width, which is 6mm). But that calculator said it was 10mm total. It didnt take the increased rim width into account.

Then I entered a 9 in wheel and it gave me the same thing, 10mm (should be about 22mm).

 

madtraction39 - yes it does...see Axis Maxx lips.

flydog - How much the face comes out? Who cares? What matters is how much the whole thing sticks out...it's usually the tire that sticks out more, if the wheel, it's the lip. The face almost never sticks out past the tire and edge of the lip.

That's the calculator I use, and it's very effective. If there was an error with it, it was operator error. The only thing it doesn't tell you is brake clearance, which no online calculator will tell you.

 

So I am Looking for 18 x 8 wheels witha 45mm offset? would that be the best fit for a 2004 TL on 18s?

Rolan