Mythbusters: Is a bike greener than a car?

[sendler]

Originally Posted by jamesqf

Well, sure :-) But where do you find an 80 mpg bike? (I mean an actual bike that you wouldn't be afraid to take on the interstate, not a Vespa-like scooter.) I've had a number of bikes over the years, from a 350cc Honda back in the '70s to the most recent 850cc Suzuki. As far as I can remember, none got much better than 50 mpg. On the other hand, I'm now driving a car that gets over 70 mpg.

The lifetime mpgUS of my 2011 Honda CBR250R is over 80. And that will improve with the new gearing. In the summer I am over 87 mpg at 65mph. If you are getting 70 in your Insight, your average speed must be pretty slow. The CBR will break 90mpg at those speeds right off the show room floor. For $4000! I used to get 63mpg in my Insight over the same commute. Now only 59. Time for some new injectors? Tire life was never more than 35,000 with the excellent Bridgestones that are made for it.

[roflwaffle]

Originally Posted by sendler

Sorry. This is not the case at all. You are getting hooked in by the treadwear adds. The tire companies are banking on the fact that you will loose the receipt or forget. 35,000 miles is tops on all kinds of cars. OEM tires and replacements. SUV's get 25,000. I see thousands of cars come through my shop per year for 28 years.
.
Anyway it takes 28 gallons of oil to make 4 tires that will be used to burn 875 gallons of gas in a car to go 35,000 miles. 56 gallons (or less since they are half the size) to make 8 tires ( I won't use even 3 in the front but whatever) to burn 440 gallons of gas to cover 35,000 miles on the bike. The bike still wins by a factor of 2. Bringing tires into this discussion is a complete non issue.

I'll believe it when I see it, or proof of it. My experience is contrary to what you're stating, but maybe I'm just lucky. I've had sets of tires rated for a 40k/50k miles treadlife warranty last that (Or a little less if I didn't rotate them) and I've had tires rated for 80k last 60k before a defect in the steel belts ruined them (They were later rated for 40k because of this). In terms of tread they were fine and would have lasted if not for the weird deformation. I currently have a set rated for 85k and 100k on two cars, so as usual time will tell.

Like I said before, I'm not talking about total lifecycle energy usage, I was just talking about the difference in embodied energy, which narrows when considering rubber use. This comment was in response to Frank's comment about embodied energy, not total energy use.

[Fat Charlie]

FWIW, I changed the OE Potenzas (hardly economy tires) on my Subaru at 54k. They would have gone a lot farther but I didn't wan't to start the winter on them as they were. And yes, I was tearing it up all the time back then.

If you're going to count tire usage as a minus for bikes, remember that they only use two at a time.

[sendler]

Man. I gotta get me some of these magic tires. My 2009 fit that my daughter drives made it to 43,000. Including two winters on snows! The summers may have had 30,000 miles on them. One was worn. Three may have had another 5,000. It will get new summers in the spring. I just asked through the whole shop and not one single person here has seen any set of tires go past 35,000 miles.

[Electictracer]

Originally Posted by Ken Fry

QUOTE=darcane;261151]The Montracer gets 53 mpg at a constant 75 mph, and emits fra more criteria emissions than a Prius in the process. This is about equivalent to 53 mpg in an EPA highway fuel test cycle. So getting 150 mpg in a streamlined motorcycle is more than a no-brainer -- and some claims are not measured in accordance with the EPA test cycle.

Having built a tiny enclosed motorcycle, I can say it is not easy to get over 100 (real) mpg in anything that most people will want to ride.

BSFC remains a challenge, as the Monotracer shows. If you have produced a bike that requires only 10 hp to maintain 75, then a 100 hp bike engine is far too large, and engine operating efficiency might be 8%. Make the engine 10 hp, and then acceleration is rotten (and top speed is 75) -- but you've bumped the engine efficiency back up to 25%.

No free lunches today.

Great point. It is a shame that the makers of the monotracer did not go that way with their design. The new breed of more fuel efficent cars seem to all have smaller engines capable of greater highend power. Sounds like a motorcycle engine to me. Of course the car engins are much more sophisticated.

[ProDarwin]

Originally Posted by sendler

Man. I gotta get me some of these magic tires. My 2009 fit that my daughter drives made it to 43,000. Including two winters on snows! The summers may have had 30,000 miles on them. One was worn. Three may have had another 5,000. It will get new summers in the spring. I just asked through the whole shop and not one single person here has seen any set of tires go past 35,000 miles.

Go look on Tire Rack. Here's a tire for the Fit that has a 65K mile warranty. First one I clicked on.

Goodyear Assurance Fuel Max

There are plenty to be found with 80k warranties. I have personally driven tires well beyond 35k before.

[sendler]

Originally Posted by ProDarwin

Go look on Tire Rack. Here's a tire for the Fit that has a 65K mile warranty. First one I clicked on.

Goodyear Assurance Fuel Max

There are plenty to be found with 80k warranties. I have personally driven tires well beyond 35k before.

Treadwear warranties are completely bogus as an indicator of expected real world tire life. You know that. They are hoping you will lose the receipt or forget. 35,000 is a high average. But it has nothing to do with the topic of lifetime fuel consumption. It's silly to keep polluting this thread with a question of tire life. Tires are completely insignificant compared to fuel usage.

[user removed]

My aunt bought a new Cadillac in 1965, the original tires wore out at 6000 miles. She asked me which tires were the best for long wear. I told her Michelin X. She replaced the tires 13 years later because she was worried about dry rot. They would still easily pass state inspection for tread wear.

My Civic VX was purchased in March of 2008 with 27,492 miles on the odometer. It was totalled and sat in an Insurance company training center for about 13 years before it was shipped to me with the rear end smashed.

I started driving the VX in April of 2008, still on the original Bridgestone tires that were made in March of 1993 (date coded on the tires). I drove it another 10,000 miles on those 15 year old tires. One trip in June 2008 I averaged 68 MPG in the VX, 300 miles on 4.627 gallons of fuel, same pump, same station, same day, with two passengers weighing just under 500 pounds.

I changed the tires because I was worried about a blowout messing up the bodywork and the fresh paint job. Changed the 15 year old timing belt at 35k miles so I wouldn't have to worry about it breaking an messing up an engine I could never replace. I can virtually guarantee you it was the only VX that was on the road in 2008 with the original tires.

When I replaced the Bridgestone RE92s on my Insight I saw no change in mileage. When I changed the Bridgestones on the VX to Michelins, my average mileage dropped by 7 MPG. I measured the tread depth on the Michelins at 25k miles and it was still 90% of the depth when new. I think the tread depth on the Michelins was almost twice what it was on the RE92s, probably a very significant factor as far as rolling resistance and tread wear. I wish I could have bought the same tires for the VX that were OE but they had long since stopped making them.

regards
Mech

[PaleMelanesian]

I must be another of those extra-lucky magic tire people.

The OEM Michelins on my Odyssey lasted 60k.
The replacement FuelMax's are now at 33k and maybe halfway worn.
My Civic has Michelin Destiny's at 41k and still legal but getting low.

Tires are really a non-issue when talking about lifetime 4-wheel vehicle costs. Back on the subject, how about a car getting 74 mpg? Sure, a bike would use less fuel, but there's not a lot there to conserve at this point.

[sendler]

Originally Posted by PaleMelanesian

how about a car getting 74 mpg? Sure, a bike would use less fuel, but there's not a lot there to conserve at this point.

We must have abrasive roads where I live.
Original MXV, MXV4, MXV4 green, Conti CH95 same tire for 15 years and the best wet performance/ price. Bridgestone RE92 a little better. 1000's of cars. Never once over 40,000 miles. Median closer to 32,000.
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What car gets 74mpg lifetime on a highway commute?