Video: Can Skinnier Tires Increase Fuel Economy?

[dremd]

new tires = lots of tread depth = worse mpg VERY TRUE I've witnessed it my self.

Maybe us EcoModders should buy used tires?

[thebrad]

Originally Posted by dremd

new tires = lots of tread depth = worse mpg VERY TRUE I've witnessed it my self.

Maybe us EcoModders should buy used tires?

I know nothing of the subject, but my car has HTR200s with only 7000 on them and they are a vast improvement over the aged Nittos that were on them previously. But to be fair I wasn't driving full out hypermiler status then. Still got like 45 mpg.

But if you want little or no tread, you could go with slicks but then you're going to have insane amounts of grip and short lifespan. Buying used could be a viable solution and ecofriendly for a period of time, but you've got to be cautious of buying tires with less than 6/32 of tread left depending on where you live.

[Chris D.]

if i find a set of 15" steel wheels to re rubber I'll run my stock tire size (205-75-15)

but I'd like to go with a skinnier tire, but they dont really cater to my perposed sizes, so i'm somewhat stuck with that being as narrow as I can go..

[cbergeron]

I've added 115's to my car:



They're clearly much narrower than the stock Aspire wheels (and our Bimmers thick 245's)

The wheels on the side are the Civic SI 195's that are seen in my avatar picture.

[guitarterry]

alot of this is in another link, and they list skinny tires also. The bad part is the other link starts talking about square contact patches like they are required. I guess those skinny tires dont work lol maybe bike racers will go to fatter tires

[Jim Allen]

Well, I guess I get to bump this thread yet again by reporting that, on my '05 F-250 HD 4x4 (reg. cab, longbed, 8200# GVW) 5.4L automatic, with 4.10:1 ratios, going from a 245/70R-17D to a 285/70R-17D did not cause a drop in MPG. In fact, it gained a skosh (though it not really outside a reasonable margin for error). Yes, I recalibrated the speedo to match the exact loaded circumference of both tires (the factory calibration was within a few millimeters for the stock tires) and am using the PID feature of my Edge Programmer to monitor instant and average FE. Oddly enough, I also lifted the front end about 2.5 inches to clear the tires and that had no measurable effect on economy by itself ( I guess going from a garage door to a 2.5 inch higher garage door...). Combined with the tires, which had approximately 1.1 inch more radius, dropped my rpms by 200 and my effective gear ratio to about 3.84:1. The engine seemed to like it. No loss and perhaps up to a 0.25 mpg gain. Seems counter-intuitive... but I'm not complaining.

Bear in mind that my ultimate goal is not the highest mpg. What I seek is to make my truck more efficient configured as I need it (as a work/farm truck that takes an occasional trip).

[yhprum]

OK, instead of a donut, what about a motorcycle tyre? They have a varity for sizes and compouds, and speed ratings.
Also I have thought about using a vaccum guage or manifold pressure guage to measure thsi sort of thing. Higher vaccum at the same speed should mean more efficiency, no?

[Peakster]

I'm wondering about the rolling resistance with a motorcycle tire. Aren't they softer than automobile tires to help traction?

[yhprum]

Depends on the compound, touring compounds can be had with hard material to limit wear. Motorcycles tyres have a round tread pattern so the ebike can maintain a contact point on the tread when it leans over. this would mean less drag, although it also means they wouls wera more in the centre on a non-leaning vehicle. There also are sidecar tyres that have a flat tread pattern.

[wagonman76]

Trailer tires are going to be a lot tougher than passenger car tires. They have a very stiff sidewall to handle a lot of weight. Typical 5 lug trailer axle is rated for 3500 lbs. Thatd be like a 7000 lb car. Plus trailers typically dont have shocks so the tires are made to really take a beating. My 900 lb (empty) utility trailer had almost no air pressure in its 14" tires for quite some time, and I never knew it because the sidewalls retained their shape anyway.