How does tire width affect performance? [Archive] - Chevelle Tech

: How does tire width affect performance?


Rookie
Jan 24th, 00, 7:36 PM
To avoid my tires scraping my wheel wells, I recently had to drop from 295/50/15s to 265/50/15s on my '72 Malibu. Somebody told me that I would get better gas mileage, because with smaller tires there's less friction, and less fuel required to push the car forward; but wouldn't that mean that I'd lose power too, because there isn't as much tire surface hitting the road and forcing the vehicle forward? Any help is appreciated.

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'72 350 Malibu
Team Chevelle #528

67drake
Jan 24th, 00, 10:50 PM
You will not lose power.You will lose traction,potentially.I doubt if you will see much gas milage change,but it is true.

elcamino72
Jan 25th, 00, 4:42 AM
295/50/15 = 26.6"
265/50/15 = 25.4"

67drake is right, you will potentaily lose some traction with the narrower tires. But where you will lose you gas milage will be in the tires diameter. I have listed above the tire diameters for the numbers you gave us. The reason that you will lose gas milage will be the new tires that you put on are smaller that the old ones. They will have to turn a little faster than the your 295/50's. It's probably only going to be a change of like 100 or maybe 200 rpm at like 55-60 MPH.

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Bryan Shook
www.geocities.com/motorcity/speedway/6673 (http://www.geocities.com/motorcity/speedway/6673)
Favorite Quote: Some people have shrinks. Some people have their garage.

Gene Chas
Jan 25th, 00, 6:02 AM
Rookie, you'll be bummin on this deal. I thought it was just my 67, but it seems that most Chevelles can take a 275/60/15 with no clearance issues. Bigger than that you need big offset in the wheels.

My 275/60's have a 28" height ( better fuel economy, but worse acceleration - a taller tire is like bumping the rear end ratio down some) and a 8.8" patch. They fit "snugly" in the rear wells - just big enough.

speedr8413
Jan 25th, 00, 6:05 AM
Air Shocks! woohoo! I put 15"rims - upgrade from stock 14's and some huge tires under there. They line up perfect with the fenderwell... Just gotta make sure I keep them air shocks pumped up. Anyway, my point is put some air shocks on it.. And take out the gas tank and put ina fuel cell, so that you can see the open flow's and diff cover. Pretty cool lookin..
I keep goin back and editing this... I don't know why I told yall about all that, I just like the idea of fat tires that don't stick out farther thn the fenderwll, and air shocks. It's a stiff ride, though

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Scott, 20
Denton/Dallas, 70 Chevelle Malibu
May the force be with you..

[This message has been edited by speedr8413 (edited 01-25-2000).]

[This message has been edited by speedr8413 (edited 01-25-2000).]

pro454chev
Jan 25th, 00, 4:33 PM
bigger tires, more traction, less gas mileage, all you need is a bigger motor! problem solved, you'll still have rotten gas mileage. never mind too many beers after blowing snow in my face for two hours.

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1969sschevelle almost finished, prostreet 454
www.homestead.com/prostreet69/1969resto.html (http://www.homestead.com/prostreet69/1969resto.html)

Rookie
Jan 26th, 00, 10:50 AM
Thanks for the advice, everyone. It could be my imagination, but it sure _feels_ like I've lost some acceleration since trading down the tires ... used to be I could stomp on it and fly down the street when I had to, and now the _engine_ still makes the same howl, but I'm just not moving as fast. Probably in my head, huh? Well, guess it just means it's time to save up for those air shocks and get the 295s back on by the summer! Any advice on good air shocks to use (the car used to have them but they leaked so bad I had to have them taken off)? As far as tires, I'm using BF Goodrich Radial T/As; anyone prefer anything different? As always, thanks for all the help.

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'72 350 Malibu
Team Chevelle #528

David Nafarrete
Jan 27th, 00, 2:16 AM
With that size tire you don't have many options for makes. That is, other than Drag tires. The BFGs are good tires anyway.

Cam
Jan 30th, 00, 9:37 PM
All else being equal, a narrower tire will net you a decrease in rolling resistance. Unless you have a wimpy motor (mine's an L6) it's not a fantasic amount. Remember that reducing unsprung weight will reduce the energy consumed trying to spin those big weenies (and brake and turn them). If you've got enough power to make a mockery of skinny tires, then by all means use a nice wide low profile tire.

Chvelle
Jan 30th, 00, 10:54 PM
Rookie,

You may want to do a search on air shocks. It seems that some folks have had problems with broken shock mounts.

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Richard Dorrough
Tulsa, Ok
'68 Chevelle (CHVLLE)
'70 Nomad
ACES # 789

Tom Kordick
Jan 31st, 00, 5:31 AM
Rookie,
What type rims are you using? I was planning on trying these tires all the way around on my 70 /monte with 8" Vette Rallies. Any rubs?

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yaounto
Jan 31st, 00, 6:09 AM
hey tom , my 72 monte carlo uses 8" rallys with 225-70-15's all around . now if your springs are as tired as mine then you will get a little rub at full lock .

here's a picture -http://www.members.carol.net/kevinwiles/johan.htm

they fill the wheel wells nicely http://www.chevelles.com/forum/smile.gif

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yaounto
Jan 31st, 00, 6:13 AM
hey tom , my 72 monte carlo uses 8" rallys with 225-70-15's all around . now if your springs are as tired as mine then you will get a little rub at full lock .

here's a picture -http://www.members.carol.net/kevinwiles/johan.htm

they fill the wheel wells nicely http://www.chevelles.com/forum/smile.gif

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yaounto
Jan 31st, 00, 6:15 AM
hey tom , my 72 monte carlo uses 8" rallys with 225-70-15's all around . now if your springs are as tired as mine then you will get a little rub at full lock .

here's a picture -http://www.members.carol.net/kevinwiles/johan.htm

they fill the wheel wells nicely http://www.chevelles.com/forum/smile.gif

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sorry about the triple post


[This message has been edited by yaounto (edited 01-31-2000).]

junglejimmie
Jan 31st, 00, 6:56 AM
"Air Shocks".......UGH!!! Try 15x8.5 with 28x12.5x15 M/T Sportsman Pros on a 70SS396 with no rub!

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Jungle Jim #105 Gold
70SS396 & 70 Malibu~
"Fight the good Fight every moment, every minute,every day. Make it worth the price you pay!"

BradleyBergstrom
Jan 31st, 00, 11:20 AM
FORGET THE AIR SHOCKS!!! I have terrible wheel hop because of them! This summer I will get rid of them once and for all!