juicebox

Hello everyone - I've been lurking around these forums for a few months and am hoping someone can concisely break down my options for a wheel and tire upgrade. The stock 245/45-17 tires on my '07 350 need to be replaced soon and I want am thinking of upgrading to 18s. I do not drive hard (well, not too hard) and I really like my current ride quality. My questions are...

1) Will going to a 245/40-18 tire size reduce my ride quality noticeably? (I live in a somewhat rainy climate that gets no snow.)
2) Will upgrading to 18s increase the tire/fender gap?
3) How much do I need to worry about wheel offset? Should I try to get wheels that match (or are really close) to the stock wheel offset?

Any answers/suggestions would be greatly appreciated. And if there are any other things I should be considering, please let me know. Thanks!

theunderlord

It's ok, you can just say Seattle.


Those two tire sizes are exactly the same diameter (25.7), so your wheel gap will stay the same.

The ride will be slightly worse, due to the smaller aspect ratio (sidewall).

Your speedometer will be 0.1% Slower.

You should try to stick as close to the current ET as possible to maintain the OE look.

juicebox

Thanks for the quick response. Couple things...

How would I go about choosing a tire that rides "softer" than others?

What does "ET" mean?

theunderlord

ET is "offset"

As long as they're not run-flat tires, they all should run about the same stiffness.

juicebox

Ah. Thanks again.

Sportstick

With all due respect, this is absolutely false. The OP should go to tirerack.com and read both the surveys and tests for tires being considered in the different performance categories. Surveys cannot be directly compared, but test quantitative scores can. You will see that ride comfort (another way to express "stiffness") varies among even non-run flat tires. Noise varies as well, and some non-automotive experts can inadvertently blend the experiences of what they hear and feel, so if comfort is key for you, look for tires which perform well on both ride quality and noise.

If your rainy climate doesn't get below approximately 45 degrees F year around, you can use summer tires. If it does drop below that temperature, all season tires are recommended, even if you have no snow. The summer tire compound will become hard and lose traction in colder temps.