My 15's need some attention so I'm sending them out for restoration. My buddy has a almost new set of 18's that I can use for the time being. They are 18x8 4.5 backspacing, and 18x9.5, 5.5 Bs.
Front wheels have 245/45 tires, rear have 285/40 but they are completely gone.
I could get 2 Nitto's 295/45 or 305/40 for really cheap.

Could I fit either one of those with no issues or do I just get 285/40?
My car is lowered around 2" rear and 2.5" front
Thanks.

 

i know its not the best comparison but my 66 has 245/45/19 on the front and a 275/40/19 on the back. fronts are a bit tall for how low it is but i could easily do a 305 in the back and iirc i was originally looking for a 315 but didnt want a drag radial. i think your generation can fit more tire in the back than mine. wheels are 19x8.5 with i think 5" or 5.5" backspacing and 19x9.5 with 6" backspacing.

 

You can run any of those sizes on that wheel. I have 17x11 with 6" bs with 315-35 tires on the back of my 72 for almost eleven years with no problem whatsoever.

 

X2^^^
What he said, if you want to easily see options go to:
https://tiresize.com/tires/Oldsmobil...71/Base-Model/

And select wheels & diameters to find matches. I've used it for a few cars and worked out very well.
Good Luck,

Brett

 

Thank you guys.

 

Another confirmation that you're good to go. I have 285/40 on 18x9, with a little room to spare on my 69. The 70-72 cars have more room in the wheel wells, lucky!

 

Thanks for the confirmation.

For anybody that's upgrading wheels this is a great calculator for tire/wheel sizes and combos.
http://www.willtheyfit.com/

and a backspacing/offset calculator. https://www.customwheeloffset.com/ti...et-calculators

 

I'm running 305 45 18 Nitto Drag radials on the rear of my 71 442. Rims are 18x10. Had to roll the lips then it clears both sides if you have the perfect backspace for your set up. If you go with a 295 45 18 on a 18x9.5 it should give you that much more clearance but again it's all about finding that sweet spot so the tire is perfectly centered so you have the exact amount of clearance on both sides. Will probably be about 3/4 of an inch for a 295. With the 305 it's just over a 1/2 inch so if your BS is off even a little your tire will rub. Measure, measure, measure. Mock it up to make sure you have it right. If in doubt go with a smaller tire for more room for error. Also keep in mind if you have a stock rotor vs. say a 12" rear rotor it will make a difference. A bigger rotor pushes the wheels out a little and then the BS will have to be adjusted accordingly.

 

Do we get to see a pic wearing those 18's?

 

I forgot to wear my MAW helmet and now I'm upgrading my front suspension to QA1 control arms and coilovers. Also replacing wheel bearings while I'm there.

 

I'm interested in how you like that set up. I already have SC&C upper control arms, tall upper and lower ball joints (stock spindles) and lowering springs. I'd like to upgrade to tubular LCA's this winter, and may go for coilovers at the same time.

 

Here are some pics of mine: These are the 18" Nitto tires even though I've made them look like RWL BFGs

IMG_0860_zpsdavzarl4.jpg

IMG_0859_zpsl6zmghww.jpg

IMG_0861_zpsgewxia2z.jpg

IMG_0875_zpsrop4iiem.jpg

A few close ups of the rear - same tire but old wheels. You can see how tight it is in these pics:
wheelwellpicofreartire-1.jpg
frontviewofrearwheelwell.jpg

 

how do you like the sc&c upper? were you able to get a good, performance, alignment? i have tall upper and lower ball joints with stock spindles. the shop couldnt get the alignment specs i wanted with my stock upper and lower arms so im just as close as they could get.

 

71Olds, those are NewGen wheels aren't they?

 

Yes they are.

 

Really like them. Too bad NewGen is gone now.

 

Agreed. I am really happy with them. If you saw them close up you would see the quality of the work that went into them. They took about a month longer than promised to be made but besides that the customer service was really good. I heard some horror stories about others that lost money though so it sounds like I got lucky. I've had lots of people ask me where they can get the wheels from and I always have to tell them NewGen is no longer in business. There is one guy that tracked down the previous owner of NewGen and he supposedly is going to make him a set.

-Joe

 

After looking at most of the LCA available, I choose QA1 because the way the coil over mounts on the LCA. It comes with a plate that distributes the load across the spring pocket instead of mounting them in the stock shock location. If you want to run stock style springs, adapter plate is available.