I suppose not.

 

Back around 2006 there were Honda official docs that said you could gain up to 10BHP running premium in your Accord. Have no idea if that's still true.

Yes the ECU is smart enough to dial back on cheap gas. Car looses power & range when you do so like everything else its a trade off. If the car is not used to tow or is not typically heavily loaded & you don't live in hill/mountain country you should not damage your engine. Depending on the actual numbers it may be a false economy.

BTW On the 17th we went out to dinner with one of my daughters & her husband. My share was $190, so the third week in January my restaurant bill has already taken a major bite ( no pun intended ) of the theoretical $250 annual savings in running cheap gas.

 

Wow i'm surprised. So have you been doing that ?

I have a 2014 328i and it states minimum required 89 octane but recommended 91 octane. The difference between mpg was about 3-5mpg per tank.

The 2.4 TLX manual states minimum recommended 91 and even with 91 octane gives me crap mileage...about 320 miles per tank (23mpg). So not sure if putting 87 or 89 would even make a difference considering its an exact same motor from the Accord.

 

23 mpg? Primarily major city traffic?

 

I would expect so my 435 does 22mpg in Raleigh Traffic & 32mpg on the highway @ 70/72mph average.speed

 

Does Acura publish how many 4 cyl TLX's they sell VS the V6 TLX each month?

 

 

Here's a recent test on fuel types from Consumer Reports, using a TLX (i4) and a Maxima

Why You Might Not Actually Need Premium Gas - Consumer Reports

 

Here is a quick excerpt of the results:

"Both sedans achieved the same fuel economy when tested with regular fuel as with premium. During this testing, the cars felt and sounded the same; we did not experience any engine pinging or knocking noise in either car when using regular fuel.

The owner's manuals indicate that you might notice a decrease in performance when running on regular, but our test results say otherwise. The 0-60 mph acceleration times were identical in the TLX and Maxima on regular and premium gas."

 

Not surprised at all. It reflects my experience as well.

 

So you should be able to try running regular or mid-grade in your current generation TLX without damaging the engine. If you experience a noticeable lack of power or hear any knock or ping, move back up at least a grade. If not, you are probably fine running the 87 or 89 octane. With that being said, if you have a weekend of back roads or trip over the mountains coming up, you may want to put the 93 in.

Our 2001 Mustang GT is supposed to use regular 87 octane. We have heard some knocking at higher load / lower RPM on the 87 and switched to 89. No more knocking at all. So apparently it can even be specific to a given car.

 

I have been running the TLX (I4) for quite some time on 89. No problem. Also have been running my 2005 TL on 89 for a long time with no problems. I did notice a difference when running 87, however. Didn't try 87 on the TLX, though.

 

Not an engine tuner here, but modern ECU got your back here. Run whatever octane (within reason- don't get lost in Mexico ), and the ECU will cover your butt with retardation, and a probably imperceptible decrease in usable HP.
Me, I run high octane because it makes me feel like I have a super high performance engine! LOL (FWIW my Yamaha outboard 300 hp 4.2l calls for 91 as well, but sip swill if necessary, and retard as needed)

 

I realize this is an old thread, and while I did read some, I did not read every comment posted here. I'm going to hestitantly add my unsolicited 2 cents from experience, even though by now you have decided what grade of gas you are going to use and why. Some vehicles you won't notice any difference with premium fuel and others you will notice a slight decrease in performance as well as fuel economy.

I used to sell BMWs. The moment they arrived on our lot they had regular fuel in them and when we sold them to customers' we filled them up with regular gas, shook their hand and the deal was done. They are one of the few cars that perform well no matter the type of gas you use, though premium gas is recommended. It is also recommended that you use a top tier gasoline from a station such as Chevron, BP, Exxon, Conoco, etc.

This applies for Acuras as well. As much as I hate spending the extra $0.60 a gallon and searching for a gas station that provides detergent additives with their fuel, if you're going to purchase a $40-45,000+ vehicle with a high performance engine, you may as well pay the cost difference unless you are on a least, generally upgrade your vehicle every 2-3 years, etc.

My previous vehicle was an Infiniti G35x that I grew tired of driving rather quickly and I often cheaper out and put 87 octane gas in it. Like the RDX, it had a 3.5 V6 and drove fine but I did notice the fuel "economy" (or guzzling rather) to suffer from the lower octane fuel. So, all you can do is weigh the scale with what is more important to you: fuel economy, performance, long-term effects to your engine (knocking), or fuel economy.

 

My TLX runs fine on regular gas. No knocking or pinging even when the pedal is mashed. My 07 type S ran like crap on regular, major pinging, knocking and the idle was even rough. I only put regular in that car once and after that only premium. I couldn't hear or feel any difference in the TLX with premium. Also some cars are "premium recommended" vs "premium required", the latter you should use premium. So to me having owned other cars that had really obvious issues on lower octane gas I observe none of that behavior in the TLX so don't worry about premium vs regular.

 

Well, at least as of the 2018 model TLX the dealer said to me: there's no harm using "regular" gas, so long as it's a "premium brand" that doesn't have less detergents.

(edit:, I see this was mentioned earlier in the thread, but worth repeating Consumer reports did a test, which actually used an Acura TLX as one of the test vehicles and could not detect a difference in gas mileage or performance:

https://www.consumerreports.org/fuel...d-premium-gas/

"The 0-60 mph acceleration times were identical in the TLX and Maxima on regular and premium gas."

So, unless you use a "custom tune", it's likely there is actually no benefit at all, to using Premium gas in your Acura TLX? (It's just like me putting the "Type S" badge on the back of my car, it makes me feel better and that's all it does.

 

 

 

Who knows if there's any real harm or not, but I bought an Acura knowing I would fill with premium "Top Tier" gas. No one that I know buys an Acura to get the most mileage out of their car and fill it with regular fuel (these buyers typically look at Honda or Toyota). Acura recommends premium for a reason, should anyone choose to ignore it that's their decision. My train of thought, again, if you consider Acura it means you can afford premium fuel. Besides if you can't afford the extra few bucks for premium fuel each week then should you really have considered a brand that uses premium fuel across their lineup?

 

Yes; to get that ultimate +3% power. No observed difference in fuel economy. Has been there, done that.

My TLX V6 runs on regular just fine.

 

People buy Acura for a premium car at a premium price, yet are scared to pay the extra $5 per week to ensure premium reliability ... go figure. If going cheap, stick with an Accord honestly. If an engine is designed one way, why change it? People here love to say that the TLX is not the same as an Accord, well engine tuning is sure as hell one of the factors.

 

That is BS.

It has nothing to do with "premium reliability".

 

So just use whatever Acura says, done .... premium recommended. Do you also cheapen out on oil grade too? That must be BS as well.

 

Love all the guys worrying that world will not know they drive a premium car & not a tricked out ACCORD getting all nutz over saving a $100 a year on gas. Nobody is saying you need 100 octane in what is a pretty mild engine but running the factory recommended blend is not going to deprive you of a cup of coffee.

 

Good for you