Since putting brand new tires on my gas mileage has been 25 mpg...stock is 195 65 15.. I have mags with 225-45-17 tires. I figure I should be getting above 30mpg on my corolla. 50-50 mix city and hwy.. 30 psi..im going to up my tires to 35-40 and take it from there. Could it just be the new tires causing a 5mpg difference? All ideas welcome!
25mpg?
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That's a good chunk wider than stock. Are they heavier over-all, as well? A few factors come into play here (Width of the tire package, weight, rolling resistance). Five MPG seems like a lot, but a loss in general doesn't surprise me.
Do the tires turn less revolutions per mile causing less miles to appear on the odometer to calculate MPG? I dont know if you have an option to change the odometer to varying sizes of tires to get a proper reading Speedometer and otherwise
Originally Posted By: oilstudent24
Do the tires turn less revolutions per mile causing less miles to appear on the odometer to calculate MPG? I dont know if you have an option to change the odometer to varying sizes of tires to get a proper reading Speedometer and otherwise
Almost identical. Within 0.3% difference from tire sizing charts.
Do the tires turn less revolutions per mile causing less miles to appear on the odometer to calculate MPG? I dont know if you have an option to change the odometer to varying sizes of tires to get a proper reading Speedometer and otherwise
Almost identical. Within 0.3% difference from tire sizing charts.
Originally Posted By: 147_Grain
New / wider tires have a greater rolling resistance than your old ones and 30psi is also taking a toll on MPG. They might also be shorter than your old ones.
There are also a lot of other variables to explain the 5 mpg drop.
Door jam aka mfr recommends running 30. I plan on setting them to 35 at least..they can handle up to 51 psi considering they are xl load range. I want them to wear evenly thats my concern as well. I dont mind a stiff ride but want tires to wear evenly. What would you guys run psi wise? Mfr states 30. Tire max is 51.
New / wider tires have a greater rolling resistance than your old ones and 30psi is also taking a toll on MPG. They might also be shorter than your old ones.
There are also a lot of other variables to explain the 5 mpg drop.
Door jam aka mfr recommends running 30. I plan on setting them to 35 at least..they can handle up to 51 psi considering they are xl load range. I want them to wear evenly thats my concern as well. I dont mind a stiff ride but want tires to wear evenly. What would you guys run psi wise? Mfr states 30. Tire max is 51.
gathermewool
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Originally Posted By: oilstudent24
Do the tires turn less revolutions per mile causing less miles to appear on the odometer to calculate MPG? I dont know if you have an option to change the odometer to varying sizes of tires to get a proper reading Speedometer and otherwise
Quick calc reveals the following revs/mile:
Stock: 807.8
New: 808
1. Width: The new tire is over an inch wider (30mm,) so contact patch and drag will increase.
2. Rolling Resistance: What types of tires were the old vs new? Economy, with min rolling resistance replaced with summer tires?
3. Weight: How much do the new "mags" weigh compared to the old?
Also, adding more info in your thread title helps. No offense, but I usually make it a point to ignore vague threads. I'm honestly not really sure why I clicked on yours, since it's not much better than a "help, I gotsa a problem" type of thread.
Do the tires turn less revolutions per mile causing less miles to appear on the odometer to calculate MPG? I dont know if you have an option to change the odometer to varying sizes of tires to get a proper reading Speedometer and otherwise
Quick calc reveals the following revs/mile:
Stock: 807.8
New: 808
1. Width: The new tire is over an inch wider (30mm,) so contact patch and drag will increase.
2. Rolling Resistance: What types of tires were the old vs new? Economy, with min rolling resistance replaced with summer tires?
3. Weight: How much do the new "mags" weigh compared to the old?
Also, adding more info in your thread title helps. No offense, but I usually make it a point to ignore vague threads. I'm honestly not really sure why I clicked on yours, since it's not much better than a "help, I gotsa a problem" type of thread.
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Did you get your speedometer recalibrated? That would make a big difference. Have you checked your speed on a GPS?
JHZR2
Staff member
Originally Posted By: Silverado12
Did you get your speedometer recalibrated? That would make a big difference.
+1.
I dont get why someone would put 17" wheels on an econobox.
Did you get your speedometer recalibrated? That would make a big difference.
+1.
I dont get why someone would put 17" wheels on an econobox.
You have added weight,and rolling resistance if wider however I suspect the diameter of the outside of the tire hasn't changed much.
So you put 17" rims on a corolla.
How about drag radials up front for track days,maybe some under car lighting,neon perhaps.
And some blue light strips for the floor. Ballin"
So you put 17" rims on a corolla.
How about drag radials up front for track days,maybe some under car lighting,neon perhaps.
And some blue light strips for the floor. Ballin"
Tire diameters are basically the same as stock (-0.1mm smaller now) so speedometer is the same as before.
I'm going to say the it is the extra rotational mass that is causing a decline and maybe adding some air will help.
Is this mpg off one tank or have you averaged it out over several?
Another factor to consider...are you "checking out" how the new tires handle? It's fun to try out new upgrades and most people will driving a bit quicker...kind of like a new exhaust.
I'm going to say the it is the extra rotational mass that is causing a decline and maybe adding some air will help.
Is this mpg off one tank or have you averaged it out over several?
Another factor to consider...are you "checking out" how the new tires handle? It's fun to try out new upgrades and most people will driving a bit quicker...kind of like a new exhaust.
I suspect your 126 hp Corolla engine is working harder, burning more fuel due to road friction caused by fatter tires. I think that because of what I learned biking. Not a hard core biker, just do it after work for exercise. After months of watching the hard core bikers blast by me on the trail (while I gasp for air) I asked one pulled over why I was so slow. First thing he said was "lose the hybrid tires, they are too fat". Swapped them out with the skinny tires and wow! My underpowered legs and lungs required literally no energy to power along at high speed. I can stay with them now, no more humiliating "on your left!" yells. (reduced to just a couple now and then
)
I'd up the air pressure. 30 PSI is fine for skinny, tall OEM tires, not low-profile 17's.
Also, how heavy are the new wheels? Some aftermarket wheels are very heavy, while others are light.
Also, how heavy are the new wheels? Some aftermarket wheels are very heavy, while others are light.
If it's an option, you could always put your original rims with the old tires on and run it through one tank of gas and see if you get 30 mpg or not.
My guess would be because you got new rims/tires that are wider and have more rolling resistance(195 to 225 is big jump). Auto manufacturers' usually put tires with low rolling resistance on their cars (especially
"non-sporty" models like the Corolla) to get max EPA ratings for marketing purposes.
My guess would be because you got new rims/tires that are wider and have more rolling resistance(195 to 225 is big jump). Auto manufacturers' usually put tires with low rolling resistance on their cars (especially
"non-sporty" models like the Corolla) to get max EPA ratings for marketing purposes.
I agree with those who say the oversized tires are overworking the engine.
As for tread wear...adding more PSI over doorjamb recommendation to overcome the extra weight/width of the bigger tires might POSSIBLY exaggerate wear on the center of the tread, especially on a light car like the Corolla. This depends on the tires' construction, so monitor them closely to get more even wear.
As for tread wear...adding more PSI over doorjamb recommendation to overcome the extra weight/width of the bigger tires might POSSIBLY exaggerate wear on the center of the tread, especially on a light car like the Corolla. This depends on the tires' construction, so monitor them closely to get more even wear.
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Originally Posted By: JHZR2
I dont get why someone would put 17" wheels on an econobox.
Because the set of 19" wheels are out of stock.
I dont get why someone would put 17" wheels on an econobox.
Because the set of 19" wheels are out of stock.
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Originally Posted By: Virtuoso
That's a good chunk wider than stock. Are they heavier over-all, as well? A few factors come into play here (Width of the tire package, weight, rolling resistance). Five MPG seems like a lot, but a loss in general doesn't surprise me.
Plain old aero drag increases as well. Back when GM sold people TWO speed automatics (the famous "Powerslide") a taller tire helped by contributing a little "overdrive" effect for highway operation, but wider tires, for all they may help cornering, don't increase MPG.
That's a good chunk wider than stock. Are they heavier over-all, as well? A few factors come into play here (Width of the tire package, weight, rolling resistance). Five MPG seems like a lot, but a loss in general doesn't surprise me.
Plain old aero drag increases as well. Back when GM sold people TWO speed automatics (the famous "Powerslide") a taller tire helped by contributing a little "overdrive" effect for highway operation, but wider tires, for all they may help cornering, don't increase MPG.
With 93k miles on the car, were you replacing the OEM tires? What size were the ones you replaced and how much wear did they have?
Upsizing wheels and going lower profile will usually be associated with higher rolling resistance and an exaggerated loss on the city mpg. The increased weight farther from the axle axis will use more energy to accelerate and decelerate.
Even when changing two "identical" sets, going from worn to full tread will impact economy, both real and apparent.
Upsizing wheels and going lower profile will usually be associated with higher rolling resistance and an exaggerated loss on the city mpg. The increased weight farther from the axle axis will use more energy to accelerate and decelerate.
Even when changing two "identical" sets, going from worn to full tread will impact economy, both real and apparent.
Originally Posted By: Clevy
You have added weight,and rolling resistance if wider however I suspect the diameter of the outside of the tire hasn't changed much.
So you put 17" rims on a corolla.
How about drag radials up front for track days,maybe some under car lighting,neon perhaps.
And some blue light strips for the floor. Ballin"
Sure, make the assumption that because I put 17 inch rims on a corolla that I am trying to mod it. Sorry you never heard of putting mags on a car to make it look better. Everything else is stock and its purely because it looks better than [censored] stock 15 inch rims/tires. Dont judge people.
You have added weight,and rolling resistance if wider however I suspect the diameter of the outside of the tire hasn't changed much.
So you put 17" rims on a corolla.
How about drag radials up front for track days,maybe some under car lighting,neon perhaps.
And some blue light strips for the floor. Ballin"
Sure, make the assumption that because I put 17 inch rims on a corolla that I am trying to mod it. Sorry you never heard of putting mags on a car to make it look better. Everything else is stock and its purely because it looks better than [censored] stock 15 inch rims/tires. Dont judge people.
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