Gas

ski1297 · 09-30-2009, 05:12 PM

What type do people run and why? Is one better at mpgs?

tadpole · 09-30-2009, 08:17 PM

I run 1st gen Insights. I typically go 450-500 miles on $20 worth of premium gas. The $.20 cent/gal difference compared to regular gas at today's prices is nearly meaningless at this rate of fuel consumption, and there is proportionately more energy in 91 octane (the highest available in my state) than in cheaper 87 octane gas . I have not done a head to head comparison, I just have faith that higher octane fuel is kinder to the little engine that could.

Gas with ethanol, which is the only thing available to us, presents a different problem. With the switch over to E-10 mileage has decreased noticeably. Last summer I could expect close to 80 mpg in the month of July. This year I would do well to get 70. Nothing to complain about in the grand scheme of things, but extrapolate this to the general public and the average car and you can see that we are not reducing our demand for foreign oil. Add to this the energy consumed for the production of ethanol and you start to wonder who was doing the arithmetic when it became mandated to add ethanol to gasoline.

Purplegate · 09-30-2009, 08:31 PM

If you make the maths for the price difference between regular and premium, which is about 20cents/gallon here, the car need to deliver +4mpg on the average tank, with the current fuel price. I personally couldn't get that much improvement, but someboby can correct me if I'm wrong... may it's possible. May be there is something I didn't do right in my test...

Since I couldn't get +4mpg improvement, I decided to stay with regular. I'm driving the I2.

Looking forward to see if somebody else would got different results using premium, and how. I would gladly try again

ski1297 · 09-30-2009, 08:40 PM

I run premium. As I did with my 06 civic. I got the I2 to save money so I dont know if I get more Mpg's with premium or with regular? It might be time for a test. Would just like to know what people run?

jraynor196 · 09-30-2009, 09:02 PM

Quote:

Originally Posted by Purplegate

If you make the maths for the price difference between regular and premium, which is about 20cents/gallon here, the car need to deliver +4mpg on the average tank, with the current fuel price. I personally couldn't get that much improvement, but someboby can correct me if I'm wrong... may it's possible. May be there is something I didn't do right in my test...

Since I couldn't get +4mpg improvement, I decided to stay with regular. I'm driving the I2.

Looking forward to see if somebody else would got different results using premium, and how. I would gladly try again

I tried premium for a while as well, and didn't see much of a difference if any in regards to fuel economy. So, I am back on regular since it is cheaper. I am on a regular tank right now and after 280 miles the MID says 61.2.

I think the only test that you could run is to get 2 insights and fill on with regular and one with premium and run the same track at the same time (roughly) and same speed. Anything else and too many variable factor in. I didn't see any noticeable jump so even if I was getting a few MPG more, the extra cost doesn't warrant the premium grade. Car says it will run fine on regular as well.

jkbrushaber · 09-30-2009, 10:08 PM

I have an 06 I1. I have been trying different gas types, but find comparisons very difficult. Temperature and wind direction/speed probably have the greatest effect. I mostly just commute to work on the exact same route, similar traffic, similar time of day. I don't think I have seen a significant difference using premium vs. regular gas, as expected. I have seen an increase with 100% gas over gas with 10% EtOH. Very few stations carry it, but I found one that always carries it. It costs 10 cents more per gal, but is worth it. Keep in mind that sometimes Premium gas (from any station that has 10%EtOH gas) supposively will NOT have EtOH in it. I have heard this many times, but is difficult to verify directly from the station employees.

Like I said, wind and temp have big effects. If you would like to try and analyze my data, I am on Fuelly.com as jkbrushaber. I usually note the octane and if 100% of my gas. If not noted, it is just regular with EtOH.

Brian1 · 10-01-2009, 09:35 AM

Higher Octane gasoline does not have more energy. The octane rating is just the gasolines ability to reduce knocking in the engine. Therefore, if your engine does not knock using 87 octane gasoline, it is just a waste of money to run on higher octane fuel. Here is a link to a definition of Octane rating.

Octane rating - Wikipedia, the free encyclopedia

jonniedee · 10-01-2009, 02:41 PM

Just because it doesn't knock does not mean that there's not more performance to be had with a higher octane. Cars now have knock sensors that help determine your ignition advance. Usually more degrees advance = more HP at a given rpm. Now with a knock sensor you do not know if there's more to be had without trying it.
Premium gets me about 1 to 2 highway mpg more with my I2 on a 80 mile commute.

wstander · 10-01-2009, 02:49 PM

Quote:

Originally Posted by jonniedee

Just because it doesn't knock does not mean that there's not more performance to be had with a higher octane. Cars now have knock sensors that help determine your ignition advance. Usually more degrees advance = more HP at a given rpm. Now with a knock sensor you do not know if there's more to be had without trying it.
Premium gets me about 1 to 2 highway mpg more with my I2 on a 80 mile commute.

So, even chemists are wrong?:

Before You Buy Gasoline - Gasoline Chemistry

Fact is that most modern engines 'adjust' to the fuel.

But, YMMV, and if you can justify the extra 20cents or so per gallon, so be it

ski1297 · 10-01-2009, 03:07 PM

Anyone know of any gas stations that dont have ethanol in the gas around Milwaukee WI?