Due to the rising gas prices and the difference of 20cents per gallon between regular unleaded and premium unleaded, has anyone here used regular unleaded in their TL? I talked to one salesman and he said that regular unleaded, if I drive like grandma, won't show much of a difference and won't tear the engine apart. Any of you all know mor about the regular unleaded?

 

Technically you could drive it on regular but why? You could NEVER accelerate hard for fear of predetonation.

 

the user manual says nothing under 91. it says if you use lower there can be additional wear on the engine parts. i always use 93 octane in all my cars so this wasn't a huge difference for me. if you think about it it comes out to about 3 dollars more for every fillup. if you get one a week its about 150 bucks a year more for the 87 and 93. but i have to admit i don't want the prices rising any more. its getting pretty high up there.

 

I have always used 91 from 76

 

By filling regular you will not save much. It will be 2-3 bucks per fill that is about $150-$200 a year. I do not think it's worth it.

 

I agree. It's your car, we cannot do anything for you. But, since you spent 35k to get 04TL, would you like to risk your car and damage it by saving this amount of money only?


I'm not saying 04TL will absolutely get hurts by it, but it's not good idea to have your engine/ECU continuing to retard timing for a long long time, IMO, due to the low octant feul.

 

I don't like paying higher gas prices any more than the next guy. I actually calculated the same number quoted above to convince myself it wouldn't bother me to pay the extra $0.20 for premium.

Another way to rationalize this, as the prices go up, the % difference is smaller for premium. I know, it's a little weak, but if it helps ???

 

I find w/premium is better gas. Car is runs smoother and seems to last a little longer. Maybe its just me but go for the premium. You can't feed your baby w/crap!!! You can go buy lunch/dinner and that would cost you the difference. So I would suggest you go w/the good stuff!! I would never feed my baby under 91 octane!

 

I find it ironic that some people will drive 10 miles out of their way to save a nickle on a gallon of gasoline (about $0.75 on a fill up?). Same for people that spend $35K for a car and cheap out on gas. This was one of the things I considered when I purchased my TL - for about 2 seconds. Treat your TL right and get the premium.

Having said that, the gas price could hike (refinery explosion in Texas, OPEC cutting 1 million bbls from export and billion chinese off of their bicycles and into a car), things could get very interesting by this summer. Still, the price of premium will only be marginally higher than regular so shouldn't cheap out then either. My 2C.

 

Usually, the ECU should retard ignition timing enough to prevent predetonation. All you would feel is a loss of power and there shouldn't be any long-term consequences. However, you'll also lose fuel efficiency. Try a tankful of regular gas and see if you can live with the lower power and if the lower gas mileage doesn't outweigh the savings.

 

Note: Correction, instead of "predetonation" I mean preignition and detonation. There is no such thing as "predetonation." Preignition takes place before the spark ignites the air-fuel mixture, while detonation takes place after.

 

It's also called "pinging."

 

Actually, I use the same rational, and it's not weak at all. Although I've never tried it on my TL, I used to do this on my Ford Explorer:

When gas prices were approaching $2.00 a gallon, I would actually start using Premium (91 octane) gas in my Explorer, which only required Regular (87 octane). Seems crazy? Yup, like a fox. You see, when I used 91 octane in my Explorer, I saw a 3-4 MPG increase in my average MPG. My MPG using Regular was around 18 MPG, and my MPG using Premium was around 22 MPG.

So, let's say that Regular was going for $1.80/gallon. Premium was always $0.20 more per gallon regardless of the price of Regular, so Premium was going for $2.00/gallon. For a full tank of gas (approx. 17.0 Gallons), I would spend $30.60 for Regular and $34.00 for Premium. Still seems stoopid, huh?

Now let's take a look at how much I was paying for gas per mile travelled, though. For a full tank of Regular gas, I would get 17.0 Gallons * 18 MPG => 306 Miles. For a full tank of Premium gas, I would see 17.0 Gallons * 22 MPG => 374 Miles. So, for Regular gas I would spend $30.60 / 306 Miles => $0.10 per mile. For Premium, I would spend $34.00 / 374 Miles => $0.091 per mile ... approximately a 10% savings in gas cost per mile!

There was a point of diminishing returns, though. This worked best the more gas prices went up, since the difference between Regular and Premium was constant. When the price of Regular approached $1.20, the improvement in MPG was offset by the relatively higher percentage of cost of Premium gas.

So ... getting back to the 04TL ... If your average MPG goes down when using Regular gas vs. Premium, you may be fooling yourself about saving money because the gas is cheaper. If the MPG difference is significant, you actually may be paying more per mile by buying Regular. I won't find out, though, because I always plan on using Premium in my 04TL - so I won't know if there's much of a MPG difference.

If any adventuresome souls out there want to test this out, you'll need to take your tank down to near-bone dry before filling up with a different gas type. You'll want to fill your tank at least twice with the different gas, and take your MPG reading from your actual purchase at the pump (don't trust the MID's MPG display). Try to approach 16 gallons or so each time to get a solid sample. Do at least two consecutive tankfuls of Premium, then two consecutive tankfuls of Regular.

Also, make sure that your testing doesn't cross over any "fuel reformulation" periods! In Arizona, certain cities require two different gas formulations during the year to reduce pollution. The changes in gas formulation will significantly affect your MPG also.

Let us know what your find!

BTW, I'm currently averaging between 26 MPG and 27 MPG for Premium in my combined city driving.

PS: Yes, I'm a friggin' engineer!

 

Another suggestion:
Here in Northeastern Ohio the county government actually lists high and low regional gas prices (east side, west side, north, south, suburb, city, etc.) It really helps find a good price (witohout driving out of the way), saving as much as $.10 per gallon. Of course, s luck would have it the highest prices for gas are at the station most convenient to my commute; reminding me regularly that I pay too much for gas.

I bet something similar exists in your area....

 

I found the same thing as GotJazz. My mileage on 87 is so low that it actually paid to put in 91. Combine that with the fact that you get better performance and less chance of engine issues, it's definitely worth it.

 

Always go with 91 or higher, the TL is a performance car and requires top notch fuel.

 

Has anyone run Regular (87 octane) most of the time? If so, what was your average MPG in the city and on the highway?

 

This engine has an 11.0:1 compression ratio Why on earth would anyone consider putting regular in. May as well get a 225 hp engine if you are going to do that.

 

I've been running Plus in my TL most of the time. There's a place near me where the difference in price between Regular and Plus is only $0.04 (Premium is a lot higher). I've been averaging 24 mpg in mixed driving, with upwards of 32 on the highway.

But I'm seriously considering switching to premium as the prices go up to see if the difference in gas mileage makes up for the cost differential (and to see the performance differential).

 

BUY PREMIUM FOR THE PRICE OF MIDGRADE !

Hey Guys ! The Shell credit card instantly credits you back 5% or more for every gas purchase. Why pay more than you have to ?

I also use Shell stations in my area that have 'Sale Days' on premium. In the final accounting I'm paying LESS than midgrade for my premium.


Jester

 

Chase Perfect Card Visa also gives you rebates on gas purchases.

 

In my car, way back to Dec., I ever gave 89 a try due to the possible solutions for subtle vibration at 1500 MPH/5th Gear/50-55 MPH. No luck. This exhaust-resonance-like tremble is still existent. Meanwhile, the MPG, 16, seems identical or a little less, we don't know 'cause it's only one tank, 14 gallons. I usually have 15-19 City MPG with 93, thus it's hard to say if 89 gave me any headache.

I have no gut to try 87, even one tank. Somebody please tell me. Thanks. :devil:

 

I have 5000 miles on my 04 TL and have used nothing but 87 octane fuel. I get no pinging and I consistently get 23 MPG or about 350 miles per tank with highway and city driving.

 

Would you hear slight pinging?
15 gallons on fillup, well into the orange light, for $3.00 more???
I drink more then that of Diet Coke per day...
I can't believe this thread keeps popping up..
How much did you pay for the car? Insurance? You're wondering about prem. costing on avg. .20 cents more per gallon, or $3.00 for a pretty well drained tank???
If you guys are going through a tank a day, this would add up... but the avg. driver that burns through a tank a week.... $150/year. If I couldn't afford that, then why am I paying $1,000 a year in insurance... $5,436/year in car payments, $21.51 on just the Mobil 1 oil at every change...etc...
Sorry...
Soap Box Mode = OFF.

 

I don't think you would hear actual pinging like we're used to from cars back in the day. I remember that the '02 knock sensors check for knock 30 times/second. The timing would probably be retarded before it got bad enough for you to hear it.

 

i'm probably one of the few who has the worst end on this. i drive over 100 miles a day. my car is 11 days old and i'm over 1000 miles into my car. i spend around $11-12 a day getting gas. i don't like to wait til i have 1/4 of the tank left. i usually fill up during my lunch break. with all that driving i would never, never (did i mention never?) would even consider/imagine me putting gas below 91. yes it's hella expensive but so is the car.

i would love it if someone who has the car longer than i have who drive similar conditions start a thread on how they maintain their car. most of the owners here do not drive as much as i do. heck i probably have more miles than owners who bought their car over a month ago

 

-- Same here!

 

--- I disagree, I have more than you... I average 120 a day... 4-1/2 months and I have 12,000 miles and still counting... I fill out about 3 times a week and spend an average of $23 each fill-up.

 

I was a wise guy, about 8 years ago I ran REGULAR in my Maxima. The car performed ok, but I had carbon deposits on the throtle. ( it was sticking )

After my mechanic did some cleaning, I went back to High Test and never had a problem again. Don't take a chance with a $36,000 car.

 

While you of course can run 87, the fuel curves of the ECU call for timing advance than can cause preignition. You could put colder plugs and back out some advance by reprogramming the ECU...but for that. As it's mentioned, you're talking about $3 per tank or something like that.

Preignition KILLS parts. A car this expensive to fix ($2000 for the bottom end plus labor) it's not worth $3 savings per tank, plus all the trouble of changing the fuel curves and timing. Most ECU's can only pull out so much timing...you can get into a situation where the ECU can't pull out enough timing to control preignition.

While the motor could take 11:1 on 87, the ECU's maps aren't designed for it. I've run 87 in my RL (another Premium only car) and never hear detonation nor noticed a difference in performance. However, I've done that only a few times by accident (pressing the wrong button on the pump), but I don't do it as habit just for the sake of a few dollars per tank.

 

which is why i put only 91 gas and nothing lower.

ulangca:
since we drive a similar distance is it enought to just do the regular maintenance (oil change, etc) or should there be extra steps to pamper my baby? do you do any other things like use mobil1 oil or stuff like that the manual says to use but you use another thing since you feel/read it was better?

 

Does the G35 also require Premium Unleaded?

 

Yes. I think the only one (in the near-luxury class) that doesn't is the 10.8:1 ES330. It runs on regular unleaded.

 

Who the hell wants a Lexus, *L*. Instead of trying to find ways to put 87 fuel in our cars, we should try to get the damm prices back down. Damm gas is $2.05 here and thats after the .10c hike this past week. Bastard OPEC people. They probably have 4 TL's in their drive ways, each different colors, and thats probably their work vehicles, *L*.

 

Mine is a CitiBank Shell MASTERCARD, not a Shell card -- does the shell card (gas only) do it too?