Does Changing The Tire Size (Width Of The Tire) Cause To Increase The Fuel Consumption?

[buddikat]

Guys,

I had 165/70-R14 Goodyear tire (stock tires) in my AK12. I have recently replaced both front tires and replaced with 185/70-R14 MAXXIS tires. The shop owner asked me to have a wheel balancing after replacing tires. I drove in the expressway and felt that my car was consuming more fuel than previous times. Could anyone tell me the relationship between increasing of the tire size, wheel balancing and fuel consumption.

Thanks.

[MasterDon]

Well theoretically yes.Wider tyres mean more rolling resistance.But the increase in fuel consumption due to a 20mm extra width on two tyres should be miniscule.

Edited April 25, 2013 by MasterDon

[Schiffer]

as MD said you would not loose much fuel over that.

but what you will be loosing is the turning circle.

where you gain points on looks you will loose points on practicality.

long time back without knowing the consequences i change my "balloon size" from 165 - 185

it didn't change the fuel figures but it reduce the turning circle as in taking U turns.

[buddikat]

Thanks MasterDon & Schiffer

Was this occurred by not doing wheel balancing after replacing tires?

[Schiffer]

nope this accord because of the laws of physics.

[nexus]

other than reduced turning circle you will get slightly wrong speedometer readings with those tyres check this link http://www.tacomaworld.com/forum/tirecalc.php?tires=165-70r14-185-70r14 on the plus side now you will have more ground clearance with those new tyres now than before which is a useful thing in SL roads.

[Kavvz]

Was this occurred by not doing wheel balancing after replacing tires?

Doesn't the shop not balance your wheels for free after they put the tires on? It takes only half a minute to do...what lazy buggers.

Did the tire shop charge you installation fees / any extra money other than the cost of the tires?

[MasterDon]

other than reduced turning circle you will get slightly wrong speedometer readings with those tyres check this link http://www.tacomaworld.com/forum/tirecalc.php?tires=165-70r14-185-70r14 on the plus side now you will have more ground clearance with those new tyres now than before which is a useful thing in SL roads.

Nope.The speedometer reading and ride height increase only occurs if he had put in tyres with a higher profile size.The profile size has remained 70mm.It's the width or the 'baloon size' as it's commonly known, that has gone up by 20mm.

[Kavvz]

Nope.The speedometer reading and ride height increase only occurs if he had put in tyres with a higher profile size.The profile size has remained 70mm.It's the width or the 'baloon size' as it's commonly known, that has gone up by 20mm.

Nexus could be right MD as the profile / sidewall / balloon size is a percentage of width.

So in this case as he went from a 70% on a 165mm to 70% on 185mm there will be a speedometer reading change due to the increased height of the tyre and the resulting change in diameter. Not too sure whether the ride height will be of any significance, but the speedo will show a difference alright...

Based on the 20mm change in width the corresponding change in sidewall / profile height is 20mm x 70% =14mm which is consistent with the information on the link thrown up by nexus

Edited April 25, 2013 by Kavvz

[MasterDon]

Nexus could be right MD as the profile / sidewall / balloon size is a percentage of width.

So in this case as he went from a 70% on a 165mm to 70% on 185mm there will be a speedometer reading change due to the increased height of the tyre and the resulting change in diameter. Not too sure whether the ride height will be of any significance, but the speedo will show a difference alright...

Based on the 20mm change in width the corresponding change in sidewall / profile height is 20mm x 70% =14mm which is consistent with the information on the link thrown up by nexus

True...apologies...got confused,forgot the profile size is marked as a ratio relative to the baloon size which is in milimetrs,thought it was the other way around.

Edited April 25, 2013 by MasterDon

[CJ5]

Guys,

I had 165/70-R14 Goodyear tire (stock tires) in my AK12. I have recently replaced both front tires and replaced with 185/70-R14 MAXXIS tires. The shop owner asked me to have a wheel balancing after replacing tires. I drove in the expressway and felt that my car was consuming more fuel than previous times. Could anyone tell me the relationship between increasing of the tire size, wheel balancing and fuel consumption.

Thanks.

Changing tyre sizes outside of the manufacturers recommended sizes can lead to various complications. For instance your speedo and odo meter will begin to give inaccurate readings too . Check this out

http://www.1010tires.com/Tools/Tire-Size-Calculator

[Shanka]

Guys,

I had 165/70-R14 Goodyear tire (stock tires) in my AK12. I have recently replaced both front tires and replaced with 185/70-R14 MAXXIS tires. The shop owner asked me to have a wheel balancing after replacing tires. I drove in the expressway and felt that my car was consuming more fuel than previous times. Could anyone tell me the relationship between increasing of the tire size, wheel balancing and fuel consumption.

Thanks.

I've had 185/70-14" in Original specs and now run on 225/45-17" for the past 7 years. Vehicle is very stable. Haven't noticed much increase in fuel efficiency. Back in those days I was told not do replace them that I will have to change the shocks often since they wear em off quickly but never had that problem either. I don't know if that varies from vehicle to vehicle but am for sure quite happier with the changed tire/rim Size. But the new Rims are light weight racing type. That might be the reason too because there are some Rims you can't carry on your own which might impact the car badly.

[kush]

By increasing the width keeping the same profile you have changed the gearing ratios of your vehicle.

If you calculate the difference of the circumference of the old tire and the new one it is approximately 5%

Consequently your speedo and odo meters will be reading 5% lea than the speed or distance you have travelled.

You need to factor that when calculating Kmpl

Technically higher gearing should give you better kmpl and less performance, however the higher rolling resistance of the extra width might counter this.

Did you feel change in acceleration.

What you should have done is use 185/65 which would have been a better option and also change the rims to a higher width 6 in to may be 6.5 provided your wheel wells could accommodate them without issues.

[leyland]

As a rule of thumb, the recommended deviation in plus sizing of the overall diameter of the stock tyre should be within 2% (+ or -) of the the stock tyres. In the OP's case, the difference in diameter amounts to 4.8% which is beyond recommended range, it would have been better had he opted for 185/60R14 which would have a diameter deviation of only -1.5% BTW, 185/65R14 would have a deviation of +1.6%, so both these options would fall within recommended range.

Edited April 26, 2013 by leyland