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New Roo! & Tire question


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14 replies to this topic

#1 Urban Coyote

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Posted 08 November 2012 - 04:59 AM

If all goes well I pick up my new to me 2009 Impreza 2.5i today after work. Woohoo! It's blue too! Not that there's anything wrong with black, white of any shade in between....I just really like cars that are a color :)

My thought is I would like to put a slightly narrower tire on it than the 205/55 R16 that are on it. Would that be possible? My hope is that it would help the rolling resistance and help with the fuel economy a bit.

Thoughts?

My current Legacy has 14 rims. Is it possible to use them on the new Impreza or is that too much of a stretch? I'm thinking it probably is.

#2 Rooster2

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Posted 08 November 2012 - 04:01 PM

IMO, a slightly narrower tire will not help fuel mileage to any noticeable degree. If it were me, I would run tire pressure at 35 psi. The car will ride a little rougher, however, the higher psi does reduce rolling resistance a little bit.

You 14" wheels will prolly not fit your Impreza is my guess. The smaller wheels will not fit over the brake caliper on what is designed for the 16" wheel.

#3 porcupine73

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Posted 08 November 2012 - 04:23 PM

Congratulations, hope it goes well. Right just going to a narrower tire is not at all a guarantee of increased economy. A narrower tire of one model/brand might have more rolling resistance than a wider tire of a another brand/model. Running higher tire pressure would probably make more difference. Or if that's really your bag getting some sort of 'low rolling resistance tire' like is made for hybrids. Whether it would actually save enough in fuel to justify the extra tire cost would be a good question.

#4 wtdash

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Posted 08 November 2012 - 06:12 PM

Hi,
Enjoy the Impreza.

Only if it 'needs' tires would it make sense to change. You'll not make up the difference by buying new ones b4 the old ones are worn out. Spend the $ on making sure your 'new to you' car's maintenance is up to date.

Info online:

.....compared the fuel economy of the lowest and highest rolling resistance T-speed rated all-season tires. We placed a fuel meter in a Chevrolet Cruze and measured the fuel consumed over our highway fuel economy test route. Results were revealing: a 1.9 mpg savings using the low rolling resistance tires in our steady-state highway circuit. That amounts to a savings of $80 a year, based on driving 12,000 miles and gasoline costing $4.00 per gallon.


Td

#5 porcupine73

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Posted 08 November 2012 - 06:28 PM

That is interesting about the low rolling resistance tires. It brings about another question not really related to this thread but ... all these commercials of people with hybrids saying 'oh I only buy gas once a month if I plug it in every night' well that's great, but if you're paying like 11 cents/kWh for electricity ... I wonder if they're really saving any money considering the extra vehicle cost. Especially when the thing ends up needing new batteries.

#6 Urban Coyote

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Posted 09 November 2012 - 05:52 AM

Thanks guys!

What about with things like going through heavy rain or snow? I drove my new roo home last night through heavy rain and it definitely handles differently from my Legacy. It does not seem to quite stick to the pavement the same and I felt a bit more hydroplaning than I would have felt in the Legacy. Is that a product of a wider tire on a lighter vehicle, or just the fact that it's a smaller, lighter car?

#7 porcupine73

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Posted 09 November 2012 - 06:22 AM

It could be those, that could also depend on the tires. Some tires seem to do very well in heavy rain, others even when they're new can't tolerate much of any water on the roadway. You could check if tirerack has the make/model tire that's on the car and see how other people have rated it in that regard.

#8 92LoyaleH4

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Posted 09 November 2012 - 07:19 AM

Unless the weathers good i wouldn't run too high of pressure...Even then your gonna start wearing the inside of the tire...

Just run the recommend tire size and pressure and do the most important thing for max MPG...Drive sensibly! (i can't do it:-p)

#9 sario

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Posted 09 November 2012 - 10:05 AM

I think a narrower tire would help some, but it wouldn't save you the cost of the new tires. If you do get new tires, look for tires that are advertised to save fuel, they should have lower rolling resistance.

When I went with slightly bigger tires my gas mileage did decrease slightly, but I think it was under 1%. I'll try and pull out the records and calculate the average today.

#10 sario

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Posted 09 November 2012 - 10:12 AM

If you’re trying to max your fuel economy you might try using a block heater. I put mine on a timmer to start two hours before I leave for work. Saves fuel, keeps me warm, and my car doesn't make that Subaru piston slap noise on cold days.

I don't know if it save's money, but we have relatively cheap power, 5 cents a KWH, so I don't care.

#11 Urban Coyote

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Posted 09 November 2012 - 10:55 AM

I should have mentioned I don't plan to buy new tires right off. I was thinking more for when the current tires need replacement.

Now I just have to decide what goodies I want to get for the new roo. Any suggestions on where to look for fun extras? I'm not talking rice-rocket stuff, more like nice external/internal touches to add a little uniqueness to the hatchback.

#12 porcupine73

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Posted 10 November 2012 - 08:23 PM

Hm I was reviewing one of my favorite Subaru stories, when the modified Justy set the world land speed record in its class, and they say:

"Tires – narrow tires were selected, and tire inflation pressure was raised to 60 psi to help reduce aerodynamic drag."

#13 sario

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Posted 10 November 2012 - 10:01 PM

I should have mentioned I don't plan to buy new tires right off. I was thinking more for when the current tires need replacement.

Now I just have to decide what goodies I want to get for the new roo. Any suggestions on where to look for fun extras? I'm not talking rice-rocket stuff, more like nice external/internal touches to add a little uniqueness to the hatchback.


Maybe a scangauge.

#14 sario

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Posted 10 November 2012 - 10:04 PM

Hm I was reviewing one of my favorite Subaru stories, when the modified Justy set the world land speed record in its class...
"

How fast was that record?

#15 porcupine73

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Posted 10 November 2012 - 10:10 PM

Oh I forget now I think it was like 123mph in its class which was the 1.0L production class, though they made a number of changes and tweaks to reach that.




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