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View Full Version : General Mine are bigger than yours are...or WTF was the PO thinking?



eagle-co94
12-22-2013, 05:55 PM
I've never seen tires this big on a DeLorean before with the exception of those with 17 or 18" wheels, but these are just too big.

The fronts were a wisely chosen 205/55/14 but the rears are a monstrous 275/60/15!!! Yes, I coudn't believe it either until I saw them up close. From what I can tell I've got the Eibach springs up front, but stock springs in the back. I'll be swapping in the rear Eibachs as soon as I wear out the tires. The good news is that the tires are Nitto NT555R's which are drag radials so they won't last forever. I'm already looking to swap these out for some proper dark grey wheels or my Cheviot wheels anyways.

I will say this though, if you're looking for better highway mileage these tires will help! They're about 2" taller than stock! It's a good thing this car has cams and headers or I don't know how this thing would get moving off the line.
http://i5.photobucket.com/albums/y154/eagle-co94/DeLorean/CIMG5735_zps4330187e.jpg (http://s5.photobucket.com/user/eagle-co94/media/DeLorean/CIMG5735_zps4330187e.jpg.html)
http://i5.photobucket.com/albums/y154/eagle-co94/DeLorean/CIMG5717_zps7b3fbd67.jpg (http://s5.photobucket.com/user/eagle-co94/media/DeLorean/CIMG5717_zps7b3fbd67.jpg.html)

Rich
12-22-2013, 06:50 PM
By the tire size charts you can figure that the rears are running 7% "longer" than stock, circumference/diameter-wise.

The fronts are about 5% "longer".

Whether or not it affects your fuel economy depends on lots of things.

The effective rear axle ratio is now 7% lower and the speedometer/odometer, which drives off of the fronts, is probably reading 5% low.

Good idea to get the rears back to a reasonable size. The DeLorean was never short of rear grip in corners. Bumping up the width of the fronts by 10mm and the rears by 40mm over the OEM widths probably only makes the car understeer more than it did originally, even if the overall limit went up somewhat.

eagle-co94
12-22-2013, 07:21 PM
What tire size charts are you using? By my calculations a 205/55/14 is actually 1.4% shorter than than a stock 195/60/14. Not sure if the 140 speedo has anything to do with it but based on GPS my speedo is reading perfectly up to "about 70mph."

Rich
12-22-2013, 09:06 PM
By the tire size charts you can figure that the rears are running 7% "longer" than stock, circumference/diameter-wise.

The fronts are about 2% "longer".

The effective rear axle ratio is now 7% lower and the speedometer/odometer, which drives off of the fronts, is probably reading 2% low.

Thanks for catching that. I goofed and the updated circumference/dia. data again from The Tire Rack specs is that the fronts are running 2% long, not 5% like I originally claimed. That's a near-match and your GPS observation makes sense in that condition.

The remaining issue about running the 205's is that if the inside front of either tire is hitting the front sway bar at full lock then you're losing a little of the turning radius.

NightFlyer
12-22-2013, 10:19 PM
Very interesting - I didn't even know that a 275 width would fit on the stock/OEM wheels. Learn something new every day :smile:

Josh
12-22-2013, 11:02 PM
Those rear tires look like balloons! I have heard that running 205s with the eibachs on the front may lead to bending the fenders?

Could you get a shot from the rear to show the width of the tires. I think that would look pretty cool with 11" wide tires!

eagle-co94
12-23-2013, 10:11 AM
Based on your description of longer and shorter, my fronts are actually shorter by 1.5% not longer. I've been using the Miata Tire size calculator for about 10 years now and find it to be the quickest way to do the comparison besides just plugging the numbers into Excel:

A B C Calc
195 60 14 =A/25.4*B*.01*2+C=23.21259843
205 55 14 =A/25.4*B*.01*2+C=22.87795276