Ecomodding an automatic '04 Civic Sedan

[Xist]

I imagine the compound provides poor traction in the snow, but a quick search did not turn up much.

[Ecky]

Most LRR tires have a poor tread pattern for snow, but that can be true of any tire. High silica content probably keeps them softer than most normal tires at low temperature so in that way they're probably superior. Most winter tires are very low rolling resistance because what makes their tread compound soft at low temperature also lowers rolling resistance.

I know it varies from vehicle to vehicle, but in the Insight, going with something other than RE92's can be worth as much as 15-20mpg. This is a car that is capable of 100mpg mind you, with excellent aerodynamics so as to make rolling resistance a relatively larger portion of energy wasted, but *if* it scaled for a Civic the same way, you'd be looking at maybe 6-8mpg at the upper end. It's likely less.

[teoman]

This is why i do not like mpg as a measure of fuel consumption. L/100 km is much more meaningfull for the conversations we have.

[Xist]

Why do you say L/100 km is a more meaningful measure? Simply because you are more familiar with it?

[Ecky]

Originally Posted by Xist

Why do you say L/100 km is a more meaningful measure? Simply because you are more familiar with it?

Na, because an improvement from 12 to 14mpg saves more money in an absolute sense than an increase from 80 to 150mpg. Also, L/100km is an absolute measure, whereas MPG is an inverse. You can't compare the actual amount of fuel saved without conversions if you use mpg.

[teoman]

Exactly.

If you say a mod gained you 30 mpg, that doesn’t really mean anything. If i have a different vehicle i will have absolutely no idea what to expect from that mod. Whereas if you say you gained 0.5l/100 km then that is usefull information for me. 0.5 l/100 km can be translated in to energy per unit of distance whereas mpg is a bit more tricky.

1l/100km (gasoline) is 9.1 kwh/100 km. From there one can calculate the improvement or waste for anything.

Its easier to calculate savings that way. Ex: 0.3l/100 km from mirror delete, 0.6l/100km from alt delete and i can expect 6.1l/100km if i do those mods to my car that consumes 7l/100km.

I am more familiar with it but typing “mpg to l/100km” in to google is not that hard. I get a number that is of no use to me without other data points to establish a relationship.

[mpg_numbers_guy]

Originally Posted by Grinder74

Why can't you run LRR tires in the winter?

Traction, what Xist said.

[mpg_numbers_guy]

Originally Posted by Ecky

Most LRR tires have a poor tread pattern for snow, but that can be true of any tire. High silica content probably keeps them softer than most normal tires at low temperature so in that way they're probably superior. Most winter tires are very low rolling resistance because what makes their tread compound soft at low temperature also lowers rolling resistance.

I know it varies from vehicle to vehicle, but in the Insight, going with something other than RE92's can be worth as much as 15-20mpg. This is a car that is capable of 100mpg mind you, with excellent aerodynamics so as to make rolling resistance a relatively larger portion of energy wasted, but *if* it scaled for a Civic the same way, you'd be looking at maybe 6-8mpg at the upper end. It's likely less.

That much? HOW? I haven't seen that much about that large of a gain in the forums here. The tires I bought cost $129.60. The Michelin Defenders cost close to $400. $270 is a lot of cash to fork out for just 1 or 2 MPG. That's more than I've spent in gas in entirety since I bought the car in January.

With your previous example of 44 vs 48 mpg, or a ~9% improvement, at my current cost of ~$0.07/mile I'd need to travel 42857.1 miles just to break even ($270 extra over a $0.0063 savings per mile). With me going to college this fall and driving 2000-5000 miles max a year starting next year the numbers don't seem to add up on my end, and that's assuming a 9% increase in MPG.

And if I pumped the tires up to 50 or 60 PSI that would help close the gap between the two tires, right?

[Xist]

From what I understand, it is difficult to measure tire difference in fuel economy. For some reason I read a post on Prius Chat where someone ranted about his new tires and replaced them immediately. Old tires are broken in. New ones aren't, so you might get worse fuel economy than with your old tires--for a while.

[mpg_numbers_guy]

My current tires have less than 4000 miles on them.

New tires came today! Not going to be mounted and balanced with my new rims until the 2nd...grrr...the wait!

Current tires are at sidewall max - 44 PSI. New tires are also rated at 44 PSI. Should I inflate my new ones to 50 PSI, 55 PSI, or 60 PSI? I don't care about the harsher/louder ride or tread wear since these tires were dirt cheap (on sale) and it'll be a LONG time before I ever put enough miles on them to need new tires.