I knew when I purchased the car that the tires were weak. They were well worn Goodyear Eagle 235/45R18 which is the stock size for the 18″ alloy wheels. I had put off getting tires while I was researching the best tire for my needs. When changing the oil to Mobil One synthetic the dealership shared with me that I might ramp up my process for selecting tires and my time was now limited by the legality of the tread (lack of) depth remaining.
The things being considered in my purchase:
- car is more of a toy than a daily driver (maybe 2500 miles per year)
- my driving style is “spirited”- I like traction and “G” force and high rpms
- very little snow in our area (Birmingham, AL)
- the Goodyears seemed to be outmatched for the car’s strength
The Altima SR has a good horsepower to weight ratio. However, mine would cut the tires loose on agressive acceleration even in third gear. It would give you a bit of a wiggle if you were changing lanes and accelerating at the same time. I wanted more stability for when I really wanted to push the envelope.
I wanted a tire that would handle wet and dry conditions. I didn’t have to worry about snow so I could shop in the summer performance tire section. In looking at my driving style and normal conditions in my area I decided I would try tires UTQG 400 or below with a temperature rating of “A” and a traction rating of “A”. One important note- I was not worried about how many miles I got out of the tires- I wanted sticky traction wet or dry.
Among the options I was surprised to see that the Firestone Firehwk Indy 500 tires were getting some great reviews from various test groups. I continued to compare them against the Goodyear Eagle, Michelin Pilot Sport, Falken, Hankook, Summitomo, Yokohama, Nitto, Bridgestone, and BF Goodrich. I did not go with the cheapest. But, I was genuinely interested in what appeared to be the “value” provided by the Indy tire series.
Now, what size? Stock or not. Well not stock! That just wouldn’t be me. Considerations:
- How wide of a tire will the rim support
- how to manage the aspect ratio
- speedometer accuracy
- fender well and strut clearance
I decided to try the 255/40R18s to see if my local dealer could mount them. They looked it up on their computor and started to get uncertain. I eased their hesitation by sharing a hold harmless dialogue. If they could fit it on there, I would live with it or pay to change it out. Deal! 
One of the many resources I utilized was this helpful site- https://www.wheel-size.com/calc/?
I really like this tire on the car! I have driven it through street and track twisties in my spirited style and only once did they lose a little traction. But, I own that as I was shifting reving to 7k!
