Premium Vs. Regular Results

[PilotguyPA28]

I'm posting this a 2nd time for all to see.........

Ok, here's the results in an '03 430LS driven in Alabama. I ran nearly 3/4 tank of regular (non-ethenol) in it the past 12 days. I filled it up when almost empty to get the best result. I drove around town normally and even floored it a few times. There is definately a power difference. How much? I can't say. There is a slight lag in acceleration which is not normal.

With premium I usually get no better than 17 in town and normally 16.5. This 3/4 tank gave me 16 exactly. So the difference in 16 and 16.5 is a 3.125% decrease in mileage. Premium is $0.25 per gallon more here and I paid $3.90 for regular. That is a difference of 6.41%.

So, from my experiment you would see a reduction of approximately 3.125% in fuel mileage but you would save 6.41% on the cost of the fuel. You have to factor the decrease in power as well as any "unknown" there may be. I calculated that will cost me about $150 per year for Premium which I am willing to pay.

I have not tested this on the highway. As soon as I get a good trip where I can check the difference on the Interstate I will post it.

Hope this helps!

Pilotguy

[Randy&Bonnie]

..

[PilotguyPA28]

The Regular didn't have Ethenol added. I won't buy gas with it.

[Randy&Bonnie]

..

[UCF3]

There are fuel stations that don't sell the Ethenol mix! Where?

[PilotguyPA28]

Alabama. It's getting more scarce, though. Ethenol is a political move. Ethenol doesn't help us at all. It ends up taking more fuel to go a certain distance when Ethenol is added.

The first stations to sell blended fuel around here priced it about 10 cents lower than unblended. After a few months they are now at the same price.

[jcrome04]

The Chevron stations up here just put up stickers on the pumps that say may contain up to 10% ethanol.....

I may have to start going somewhere else!

[VRicherson]

I just bought a 95 ls 3 months ago. I started out using regular gas. This was before they changed to summer gas. I was getting 22mpg. I started using the 93 premium gas. I check my mileage every fill up. I get about 20 mpg now but it is all short trips, probably what would be called city driving (< 20 miles per trip usually). I am trying different gas stations. I will try a gas station for 2 fill ups and see the mileage using that stations gas. Raceway gave me 20 mpg with premium. So far first tank of Shell premium gave me about 20mpg. Everywhere I go now has 10% ethanol. I am going to try chevron next, then switch back to regular and see if I notice any mileage difference. That has been my experience so far. 5,000 miles since I bought the Lexus.

I did get 31 mpg on a 120 mile interstate trip (4 gallons) one time a few months ago. I'd like to do more tests like that but I only take long trips every so often and usually do a lot of city driving once I get to my destination. I only did this one time test the mpg for all interstate. I have not had another opportunity.

I also live in Alabama (Montgomery, Wetumpka area).

[PilotguyPA28]

I also live in Alabama (Montgomery, Wetumpka area).

Hey neighbor (Tuscaloosa here). Any kin to Jim?

[HankJ]

Hey pilotguy,

I live in MGm and get about well over 22 mpg for over 140,000 miles (calculated through gasbuddies, not trip computer). Why is your so low? I drive a 2004 LS4430 UL.

ciao

hank

[PilotguyPA28]

I guess it depends on how you drive. Are you saying you get 22 city? If so, you must be doing bypass driving. If that is your combined driving city/highway then that would be about right. It all depends on the type driving and the local roads. I get 26 highway at 75mph, 29 at 65, 32 at 55.

[GKLCPA]

I've been burning regular ever since gas prices started getting near $ 4 per gallon. Other than a very slight loss of power, I've not noticed any other difference. My mpg is the same. I agree the savings over premium is small, but it might as well be in my pocket versus the oil company's.

[Alexander the o.k.]

This has been bothering me awhile. When you guys say 'regular', you mean mid-grade right?

It's been about 1000 years since I last used 'regular', and back then, they used to make the gas pump nozzles one size for 87, and 93oct a different size so you couldn't mix them up.

Are they the same size now?

I use mid grade all the time without a hitch and get about 18-20 in 80% in town/20% highway. (10% ethanol)

edit: Also--- wouldn't you get some pre-detonation if you are actually using 87oct?

[PilotguyPA28]

This has been bothering me awhile. When you guys say 'regular', you mean mid-grade right?

It's been about 1000 years since I last used 'regular', and back then, they used to make the gas pump nozzles one size for 87, and 93oct a different size so you couldn't mix them up.

Are they the same size now?

I use mid grade all the time without a hitch and get about 18-20 in 80% in town/20% highway. (10% ethanol)

edit: Also--- wouldn't you get some pre-detonation if you are actually using 87oct?

Regular is regular (87) and mid grade is midgrade (89-91). Premium is 93 around here. I have found that Shell around here does not have ethenol and has no plans to use it. The car will adjust for the grade, thus no pre-detonation. Buy Shell and BP since they don't buy from the middle east.

[DisBoyMartin]

This has been bothering me awhile. When you guys say 'regular', you mean mid-grade right?

It's been about 1000 years since I last used 'regular', and back then, they used to make the gas pump nozzles one size for 87, and 93oct a different size so you couldn't mix them up.

Are they the same size now?

I use mid grade all the time without a hitch and get about 18-20 in 80% in town/20% highway. (10% ethanol)

edit: Also--- wouldn't you get some pre-detonation if you are actually using 87oct?

Regular is regular (87) and mid grade is midgrade (89-91). Premium is 93 around here. I have found that Shell around here does not have ethenol and has no plans to use it. The car will adjust for the grade, thus no pre-detonation. Buy Shell and BP since they don't buy from the middle east.

hi there... i just bought a 92 ls400 and i didnt know which gas to put in.. so it is ok that i used 87 oct at shell?

[eatingupblacktop]

This has been bothering me awhile. When you guys say 'regular', you mean mid-grade right?

It's been about 1000 years since I last used 'regular', and back then, they used to make the gas pump nozzles one size for 87, and 93oct a different size so you couldn't mix them up.

Are they the same size now?

I use mid grade all the time without a hitch and get about 18-20 in 80% in town/20% highway. (10% ethanol)

edit: Also--- wouldn't you get some pre-detonation if you are actually using 87oct?

Regular is regular (87) and mid grade is midgrade (89-91). Premium is 93 around here. I have found that Shell around here does not have ethenol and has no plans to use it. The car will adjust for the grade, thus no pre-detonation. Buy Shell and BP since they don't buy from the middle east.

hi there... i just bought a 92 ls400 and i didnt know which gas to put in.. so it is ok that i used 87 oct at shell?

Again, try the search tool. The vedict is out on this one. There is a ton of opinion out there. Lots to read. My preference is top tier prem fuel. My car runs perfect with that fuel. No loss of power, mileage, no pinging, keeps the TB, injectors, and plugs cleaner imo. Others don't mind whatever slight reduction in power or mileage there is in exchange for dollars at the pump. Read and decide.