Fuel Economy, Hypermiling, EcoModding News and Forum - EcoModder.com - View Single Post - 155/80-13 tires (looking for LRR options)

Roman · 12-29-2010, 08:55 AM

What i would like to know wil a smaller rim make effect.

For example i now have 185/60R14. I need to replace my tyres, so i will look voor some smaller like 155 and maybe even LRR type (when not much more expensife).

The problem i have now is that my tachometer (or how do you call that thing) give's to much. Like 10% to high. When i drove 100 km there will be 110 on my dayteller. So i need 10% less measure. (correct me if im wrong)

I found a site to calculate it (it's a dutch site) TECHNIEK - BANDENMAAT / TELLERAFWIJKING

So when i go from 185/60R14 to 155/60R13 than it should be ok.

But i could also use 155/50R14.

But which one would better for FE? Lets assume it's the same brand tyre and same type/brand rim.

But the measure wil increase from 71,5 inch to 63,8 inch. So the wheel has to make more rotations for the same distance. When i traveling whit the same speed as used to is it that the engine runs on more RPM (making also more noise) or not? When it makes more RPM for the same speed will it use more fuel?

Good is also that the hight will increase from 57,76 cm to 51,62. That is 6,14 cm zo 3,07 cm / 1,21 inch lower car, think that this would also pritty good for FE.

12-29-2010, 08:55 AM	#54 (permalink)
Roman EcoModding Lurker Join Date: Aug 2008 Location: Maassluis - Netherlands Posts: 51 Golf D - '83 Volkswagen Golf GL 90 day: 42.79 mpg (US) Thanks: 0 Thanked 0 Times in 0 Posts	What i would like to know wil a smaller rim make effect. For example i now have 185/60R14. I need to replace my tyres, so i will look voor some smaller like 155 and maybe even LRR type (when not much more expensife). The problem i have now is that my tachometer (or how do you call that thing) give's to much. Like 10% to high. When i drove 100 km there will be 110 on my dayteller. So i need 10% less measure. (correct me if im wrong) I found a site to calculate it (it's a dutch site) TECHNIEK - BANDENMAAT / TELLERAFWIJKING So when i go from 185/60R14 to 155/60R13 than it should be ok. But i could also use 155/50R14. But which one would better for FE? Lets assume it's the same brand tyre and same type/brand rim. But the measure wil increase from 71,5 inch to 63,8 inch. So the wheel has to make more rotations for the same distance. When i traveling whit the same speed as used to is it that the engine runs on more RPM (making also more noise) or not? When it makes more RPM for the same speed will it use more fuel? Good is also that the hight will increase from 57,76 cm to 51,62. That is 6,14 cm zo 3,07 cm / 1,21 inch lower car, think that this would also pritty good for FE. __________________ NOW INTERACTIVE! Joystick controls Fry's left ear. Last edited by Roman; 12-29-2010 at 09:24 AM..