87 Octane Fuel in a 2005 TL

RTM. Don't do it. You want to buy a $36,000 car, then attempt to save two dollars on a fill up..?

It's not worth the few bucks per year you might save for the possibility of screwing up your $35,000 car. It's 11:1 compression requires 91+ octane. Will it run on less? Yes, but it's not worth the risk or the loss in performance. You're not saving that much.

Not to mention that you will probably get better mpg with 91 so the cost isn't as bad as it seems. Saving a little money is a great idea except when it is at the cost of ruining an engine. Ever see a piston from an engine that has been detonating? Lots of dents and holes from the knocking.

Given the compression ratio of this engine, I would have to agree that running at anything below 91 octane would almost certianly produce damage to the engine at some point. I was just interested in others views on this.

Any, by the way, higher octane rated fuel in and of themselves do not produce higher fuel mileage. In fact, all things being equal, (meaning engine and value timing, etc). higher octane and performance number fuels produce lower fuel mileage, as the fuel has a lower energy content per volume. This is due to the mix of aromatics added, and other non-energy loaded chemicals for instance, to get the higher detonation resistance.

In the case of the modern engines that have dynamic timing control, detonation sensing and variable valve timing, the lower octane fuel would most likely produce lower mileage as the engine compensates to protect itself.

Paul

I was test driving a TL at my local Acura dealership two weeks ago and asked the salesman if the car required 91+ octane. He said that it can improve performance but it's not necessary and that every car on their lot was filled with 87.

I was test driving a TL at my local Acura dealership two weeks ago and asked the salesman if the car required 91+ octane. He said that it can improve performance but it's not necessary and that every car on their lot was filled with 87.

He's an imbecile.

Check the owners manual. It will tell you the fuel requirements. Most modern cars have knock sensors that will retard the spark if they sense knock. So you can use the lower octane fuel, but performance will suffer. So it is not a case of getting more if you use higher octane as much as it is that you get less if you use the lower octane gas.

-------------- Alex

The new Hyundai has a V6 and runs on 87 octane gas. Maybe that car would be more to your liking.

Or a nice Sunbird.

Huh? Honda is currently marketing that they all require 87. Premium is an option for higher performance. I believe the wording in the owners manual is now along these lines. I have no doubt all the cars on the lot are filled with 87.

Nothing has actually changed except Honda now apparently trusts the knock sensor to protect the engine, at least until the warranty is up.

You should drive one. They really have come a long way. The stylings is also getting better.

GM still has a long way to go.

------------- Alex

In case anybody missed it, I was trying to be sarcastic. In the sense that the OP wants an Acura, but balks at putting premium gas in it.

MY 2005 TL manual states clearly that the engine is designed for operation with 91 octane fuel, but 86 octane can be used temporarily if 91 is not available. It states the use of 86 octane fuel over a long period can cause damage to the engine.

I would think that's pretty clear. I believe they would say "you were warned".

Paul

From the Acura web site:

Recommended Fuel Premium unleaded 91 octane

Around here, Premium is always 6 cents more per litre than regular. So if I put in 50 litres every fillup, I will always pay $3.00 extra per fillup for Premium, no matter how expensive gas gets.

Well, there you go. I would think that would put the issue to rest for that particular car.

Now if they would similarly clear up the wording on some of the other models...

Like everyone said.

It's an aluminum engine, and even if the knock sensor ... does whatever it does, retards the spark or something, to reduce knock, you might still have it occurring a few percent of the time, which won't do the aluminum any good.

Hmm, anybody know how smart the software is, will it keep pushing the timing back towards knock, or will it adjust for the life of the trip? Just wondering.

J.

I'm not sure how Honda does it, but on the Nissans, it resets every time you start the car.