I was wondering if 20x9 with a +45 offset will fit the front of a 2008 sedan.
What about 20x10 with a +38 for the rear? Will these fit?

 

Yes, these offsets should work on your car.

 

After reading some of these threads it seems that the front will be a bit conservative. Would i need spacers in the front if I'm trying to get it flushed?

 

Assuming you're upgrading from the OEM 18" wheels:

Your front rim will extend an extra 21mm
Your rear rim will extend an extra 31 mm

To bring your front rims in line with your rear rims, you will need 10mm spacers in the front. I recommend test fitting the rims before buying to make sure they're not sticking out too much.

 

Yes. That is really conservative. I would recommend something closer to 20x9 +30 if you are lowered. I am running 20x9 +25, and I am flush with a mild drop (Eibach springs with -1.6 degrees of camber). The 20x10 +38 is more aggressive, and you will need a drop and negative camber for it to be flush.

If you can post your plans for lowering, and tire sizes you are going to run, I can give you a better idea as to exactly what you will need to do.

For reference, you can look at my current setup:
https://www.myg37.com/forums/picture...rs-d-20-a.html

 

9 +25 and 10 +30 should be pretty good.

 

I got a set of Tien H-techs and I plan on running 235/35/20 in the front and 255/35/20 in the rear. Are the tire sizes too small or will it be fine? I don't like that tucked look with negative camber. Just a more flush look. I dont know anything about rim offsets and the best tore sizes so any help would be great. Thanks.

 

Thats really nice!!! So just because you have negative camber in the rear does that mean that the rear tires will look slanted?

 

Negative camber will cause the wheels to tuck in more at the top of the wheel, but won't necessarily give you the tucked look if you go with the right offsets. When you lower your car, it is all about the right offset. Negative caber will look like this /\ from the back of the car. You can't really even tell until you get up to -2 degrees, or so.

The H-Tech's will drop you car around 1.5" all around. This will also mean that you will have around -1.5 degrees of negative camber if you do not add camber arms. I would install the wheels and tires and see what you think. I would also recommend a 15mm spacer on the front 20x9 +45 to get it more flush. It will look tucked in with no spacer. I think you will be OK on the rear with the 20x10 +38.

Once you see what it looks like you can decide if you want to add camber arms to adjust the wheels out some. This will also help with tire wear. It's also more parts to install, and more things that can go wrong....

If you want more of a stretch tire look, the sizes you have are OK. I would probably go with a 255/30 on the rear. It is a better match with the 235/35 front. I would personally go ahead and go up to 245/35/20 and 275/30/20 tires just to get some meatier tires (both in width and sidewall). These are also closer to the stock diameter, and closer in size to each other.