Quote:
Originally Posted by cackalak
Yes, I'm sure the auto manuf. have tested various sizes and gearing for the best MPG's, especially now days. But I agree, it is fun to try and trump the engineers. 
Going to skinnier tires, but the same overall height will help. I have tried to find another tire size for my Civic, but have had a hard time. My current size is the same at 185/65/14 and was looking for a 165 or 175 equivalent (keeping the overall diameter the same). But that would mean a 73 or 69-series tires (respectively)....which don't exist. But, the closest is 175/70/14's. I am wondering if it's worth it. Tirerack has several of these available. On my next tire change, I might spring for them.
Also, I have the HX rims, which are very light. If you're on stock steelies, I'd suggest trying to find a set of HX rims. Or even aftermarket 14" alloy rims would help. |
cackalak,
I had a set of 175/70/14 snow tires on the Civic a few years ago. They are very narrow, and the ride felt very wobbly and disconnected. I got rid of them after one season. Unfortunately, I didn't keep track of fuel economy back then. However, they were full tread snow tires, so they're not the best tires for FE anyway.
Anyway, based on the above 'research'. Unless you're driving an aerodynamically modified civic on flat ground at speeds under 65mph, you'll probably find that you get the best FE with the 185/65/14's. Especially if you have lighter 14" rims.
Also, check Craigslist. That's where I found a cheap experimental set of 185/65/15's. I'm glad that I didn't pay full price for that!
If you do get a set of 175's please post an update.
Thanks.