95 Civic EX Tire Size

[KrazyDawg]

The stock size listed for my 95 Civic EX Coupe is 185/60R14 according to TireRack. 185/65R14 is currently installed. I have an invoice from the previous owner showing it was installed by Big O Tires. My tires need to be replaced soon and the quote I received was for a 185/65R14 instead of stock.Will there be any difference or advantage in going up a size? The tire that was recommended to me was the Toyo Extensa A/S tire but the size quoted might be a mistake.

It was noted by one person that going up a size reduced their MPG by 5 MPG.

[theholycow]

According to the tire size calculator:
22.7 inch diameter -> 23.5
887 revs per mile -> 859
60 mph on your speedometer will mean you're going 61.9
Total of 3.2% difference

It's very minor. How's your torque? Do you have a little extra torque? If so, the slight increase in gearing could benefit your FE.

What are the details on the person who lost 5mpg? Was he running the same pressure? Did he figure in the odometer error with his calculations? Did he rollout the old and new tires to measure their circumference as installed? 5mpg is pretty chunky - even if he was getting 50mpg it's 10%. That sounds possible, if some or all of these conditions were true:
- The new tires he got had abnormally high rolling resistance, and the old ones had abnormally low RR
- The size change was more extreme than the one you're contemplating
- His car was geared too high

[KrazyDawg]

Originally Posted by theholycow

According to the tire size calculator:
22.7 inch diameter -> 23.5
887 revs per mile -> 859
60 mph on your speedometer will mean you're going 61.9
Total of 3.2% difference

It's very minor. How's your torque? Do you have a little extra torque? If so, the slight increase in gearing could benefit your FE.

What are the details on the person who lost 5mpg? Was he running the same pressure? Did he figure in the odometer error with his calculations? Did he rollout the old and new tires to measure their circumference as installed? 5mpg is pretty chunky - even if he was getting 50mpg it's 10%. That sounds possible, if some or all of these conditions were true:
- The new tires he got had abnormally high rolling resistance, and the old ones had abnormally low RR
- The size change was more extreme than the one you're contemplating
- His car was geared too high

I don't notice any difference in torque. I've been running non-stock tires since I purchased the car 1.5 years ago but haven't noticed they weren't stock until I started researching new tires. The funny thing is the shop I take my car to quoted me for a larger tire size but I think it might be an error on their part.

The person that lost 5 MPG was driving a 2002 Civic but I don't know the details. http://townhall-talk.edmunds.com/dir...ded/224#MSG224

The Michelin HydroEdge GreenX is a tire I might consider. It's the only LRR tire I've been able to find for my vehicle.

I found a tire calculator similar to the one you used for calculating your speed when going up a tire size. http://www.discounttiredirect.com/di...foTireMath.jsp

[theholycow]

Oh, I re-read your post...earlier I missed that you're running the size you were quoted for, not the stock size. Well, it's working ok for you now...

The report of 5mpg lost is second-hand at best. Anonymous guy posts on the internet "A friend of mine did that and took a hit on fuel economy by 5 mpg" without specifying anything...I wouldn't worry about that report.

[KrazyDawg]

Thanks for your input. I went forum crazy and posted on gas savers, cleanmpg, and honda tech, so I could get some more feedback. I also felt 5 MPG was a bit much.