vgr926

Hello, everybody,

I've been using the prescribed premium gas (octane rating 91) so far in my 2.4L TLX, and the mileage and performance seem pretty reasonable so far. I was wondering if someone experimented with lower grade gas and what was the impact (if any) on the performance and mpg?

Thanks.

ConradValmont

You bought a $30K+ car, you can afford the recommended Premium Unleaded. Using a lower grade won't affect mpg much, but might affect engine performance.

FredS

I have driven a 2007 RL 170,000 miles before selling using the middle grade 89 octane and 75,000 miles on my 2010 RL and again have never had a problem. I would however not go to the 87 octane. Save your money. I looked for two M.I.T. graduates opinion which is linked.

Premium vs. Regular | Car Talk

Another opinion:

Save Money and Stop Buying Premium Gas

From Car & Driver:
Our tests confirm that for most cars there is no compelling reason to buy more expensive fuel than the factory recommends, as any performance gain realized will surely be far less than the percentage hike in price. Cheapskates burning regular in cars designed to run on premium fuel can expect to trim performance by about the same percent they save at the pump. If the car is sufficiently new and sophisticated, it may not suffer any ill effects, but all such skinflints should be ready to switch back to premium at the first sign of knock or other drivability woes.

From USA Today:
The main advantage of premium-grade gas is that it allows automakers to advertise a few more horsepower by designing and tuning engines to take advantage of premium's anti-knock properties. But auto engineers generally agree that if you use regular in a premium engine, the power loss is so slight, most drivers can't tell.

"I go back and forth, and I'm hard-pressed to notice" whether there's regular or premium in the tank, says Jeff Jetter, principal chemist at Honda Research and Development Americas. He drives an Acura designed for premium.

Import brands, especially, use premium fuel to distinguish their upmarket models. Most Toyotas, for instance, are designed to run on regular or midgrade, while the automaker's Lexus luxury brand prefers premium. Same with Honda and its Acura luxury line.

"Generally, the more expensive the vehicle, the higher the expectation for performance and the more the customer is willing to pay for fuel," says Pete Haidos, head of product planning for Nissan in the USA.

Stew4HD

Even the Acura One-Pack rep said that Premium is "recommended" but sure sounded like it wasn't necessary.

You will get the snipe posts saying that "if you can afford to buy an Acura, you can afford the premium gas prices".

At the end of the day, I don't think you will hurt your car by using with regular but you won't get the best performance out of it either. You can choose to do as you like

tlxsteve

I guess you are ready to start another food-fight. Seems this question comes up a lot in this forum and everyone ends up fighting each other.

I am not looking forward to reading this thread. I see a lot of blood and opinions on the horizon.

smoore

I did try using regular on my 2004 TL and I did get some occasional knocking when driving aggressively and went back to premium. If I owned the car and planned to keep it a long time, I think I would stick with the premium gas. However, if you are leasing and don't have any performance problems, you might be tempted to use regular or mid-grade.

I will be moving from a 2011 G37XS Coupe to the TLX SAWD Elite at the end of next month. With gas prices dropping and 25% increase in fuel economy over my Infiniti I think I will be happy to fill with premium. The G37 cost a fortune to keep gas in.

ggesq

iTrader: (1)

RCJD

not again....

WheelMcCoy

But is that premium blood or regular blood?

Yes, this question comes up over and over again, and produces the same responses.

panamera125

Tried using regular in the e46 BMW 328i, and switched back to premium after only about a month. If the engine was revving under 2000 and you tried to speed up, it would lose power and sort of drop revs and almost stall. Not a fun experience when trying to power up a hill... (The 328i recommends premium, and plus grade seemed to work better, didn't seem to really affect the car at all. Now that it's higher in the milage, though, just been keeping it on premium)

Archie

What are you actually trying to save? 30 cents per gallon? $4.50 per tank? Depends from millage driven per month $12-15? Come on.. When one pays $35-40K for car trying to save 15 bucks per month looks ridiculous

MedX172

I had a mental barrier about Premium Unleaded too and had to rationalize it with math as well. Right now (look at those prices drop!) the difference in price between Premium and Regular unleaded at Shell is 20 cents/gallon with prices falling. I've seen the spread higher of course, lets say 0.45 cents more, like when gas blew through $4/gallon here in California.


I've got to ask myself, if the $3.44 - 7.44 per tank savings is worth not following the manufacturer's recommendations for insuring my $43k+ purchase is running well. I'm a low mileage driver, but even if I filled up twice per week at current prices, the peace of mind would be worth the additional $27/month at that mileage rate. As it stands I'm looking at $6.88/month on Premium. Doing the math helped me assuage my long standing mental block about paying for Premium gas.

crownr0yal

These are the terms that make sense to me. It's just not worth risking whatever for the little savings. Also, why I didn't go for a Golf TDI v. gasoline model, but that's another story for a different forum.

Flipster23

iTrader: (15)

Use premium it's only 20 cents difference or so a gallon.

clocks

Where is that? Years ago when I had my TL, it was about 30cents more. Then I had an Accord for two years. Now with my TLX, being back to buying premium, I am seeing 40-55cents more per gallon.

tlxsteve

Nothing but repeats on the forum tonight.

Guess it's nearly Christmas time.

:hohoho:

vbx

Sounds like it's okay to use 87 according to the manual. Unlike Infninti which warns drivers not to use anything under 91 for their 6MT's.

Infiniti also says if 91 isn't available, we can "temporarily" use something lower, but we should replace it with 91 immediately, AND not to drive like a ricer when on anything lower than 91.

CoquiTSX

+1

BEAR-AvHistory

Hey guys run what's on the gas flap tag. 93 octane is under $2.50 a gallon & 89 is $2.30

Stew4HD

I paid $2.67 a gallon for 93 here, regular is $1.96. That is the widest margin I have seen between regular and premium.

hddnav

Considering that the average car sale price in the US is about $30k, spending that amount on a TLX by no means indicates a luxury car purchase.

Would you say that a $30k Accord V6 automatically justifies premium gas? If not, why does a TLX?

ggesq

iTrader: (1)

Because that's what is recommended.

A V6 Accord has a 10.5:1 compression ratio. A V6 TLX has a 11.5:1 compression ratio.

wlkeel

Wow! I've never seen a spread like that. It's about 20 cents here in So California.

clocks

I got gas the other day, and the spread was 50cents. About a week ago I saw a station where the spread was 70cents! I'm going to try a different station next time and try to find it cheaper.

hddnav

Exactly. Recommended for best performance, but not required to prevent engine damage.

Unlike my TL, which REQUIRES premium to avoid engine damage (says in the owners manual).

Which goes to show that the argument that owners, since they purchased a $30k TLX, shouldn't be considering regular unleaded and are misguided is not necessarily true.

Now, if we're talking about a BMW 5-series or Lexus GS, the "if you couldn't afford premium you really couldn't have afforded the car in the first place" argument would be much more applicable.

CanTex

The key word is "Recommended", not required. Premium is only needed for running the engine near its capacity, as in, sporty driving and maximum acceleration to eke out a few more horsepower. For day-to-day driving and even some spirited on-ramp merging, 87 octane is just fine.

I have talked to several knowledgeable MDX owners over the last few years. All have only used only Regular only with no issues, no knocking. Even the Lincoln dealer, where I test-drove an MKC, gave me the "What planet are you from?" look when I asked about using Premium ("Required" on the MKC). Never ever do they use Premium or recommend it to their customers.

My old '01 TL that had Premium for the first 120K miles and Regular for the next 70K miles in the hands of my son had no problem engine-wise. (just the infamous transmission issues.)

So it gets down to the "boy racers" and the rest of us who drive normally.

Stew4HD

IMHO, you can use regular if you want due to the term "recommended". That is up the owner. There are many here will always look down on those that do use regular instead of premium.

ggesq

iTrader: (1)

You didn't address the second part of my statement. Your 4G has a 11.2:1 compression ratio. Why is it that your 4G requires premium but the TLX doesn't? Could it be that marketing for the TLX is targeting those who don't like spending more on fuel?

What damage is going to happen to your 4G if you don't use premium? Just wondering.

Sent from my iPhone using IB AutoGroup

04WDPSeDaN

iTrader: (1)

You as well as some others are only looking at this in a very basic form, Performance. You guys fail to realize, it's not only a performance gain but over all has benefits that I will explain. Using 87 octane which in today's world has ethanol mixed in. The gasoline is no longer 100% clean. Using highest pump octane has nothing but benefits. With most modern engines using higher compression, turbos and direct injection it will only be best to use premium. The amount of carbon build is 87 creates is outstanding. You as a driver probably won't notice the lack of performance or overall general running condition of an engine. To further understand this, you must understand how an engine works. I'm not here to teach automotive 101. Carbon build up will cost you more in the long run. You have a higher chance of injectors losing efficiency or failing, you have a greater chance of oxygen sensors failing quicker. There's a greater chance of carbon build up on top of the piston heads..

Without getting more into these worthless "fuel" discussions, in short and simple. With the cost of gasoline prices AS OF TODAY, you can afford to use 91 or higher. You will get better fuel economy as well as a vehicle that runs more efficient. The yearly difference on average is about 100-200 more for premium vs regular. This isn't a huge savings towards your monthly bills, mortgage, or coffee runs. In fact, you probably spend more on dunkin/starbucks coffee in the year vs if you switched to premium. At the end of the day, this is your vehicle you do whatever you want, but understand education in this topic goes a long way. What would I know? Certified technician for 10 years including an Acura certified technician. I've pushed enough wrenches in my life to understand the long term effects of regular vs premium.

Most of you guys should read this
http://www.virginiaautoservice.com/a...impact-engine/

"There are some things that will cause carbon to build-up faster that those with cars that are prone to carbon build-up problems should avoid. Filling the tank with low grade gasoline which is less purified and usually has a higher concentration of contaminants can increase carbon build-up in the engine. If the ratio of fuel to air is off, as mentioned above, carbon will accumulate more quickly. Using the car primarily for short trips can also increase problems with carbon build-up as the engine doesn’t run long enough or hard enough to get hot enough to burn any of the carbon off.

The cars that are at the highest risk for carbon build-up problems are those that use DI, although not all cars that these types of fuel injection system have experienced this issue."

My wife has the new Kia Optima, direction injection engine. It's recommended for regular, but hasn't seen regular since it was build in the plant. In her owners manual it stresses to use a fuel system cleaner every 7K. This is because when you use a direct injection engine with regular gasoline and the amount of carbon build up that will develop is outstanding. I only use 93 and a system cleaner every 10K. Just like a human body, you put in crap, you become less efficient.

CanTex

Great input! Yes, I can afford 91 octane, but from a mere driver's perspective I see no apparent gains for the medium-term. Most drivers may never experience any issues at all for as long a they own their car. I find that using Top Tier gasolines tends to keep the injectors clean. (Unscientific experiment re carbon buildup: '99 Accord using cheap vs Top Tier: A couple of expensive injector flushings with using cheap gas, none after converting to better fuel. That car went ~190K miles before moving it out.)

Keep in mind, this is for the 2.4 where Premium is only Recommended. On the V6, sure, Premium only.

Something about Top Tier fuels eliminating carbon build-up, can't remember the commercials right now.

I'm sure Acura/Lincoln/Whoever has factored into their designs that Joe Average will just use regular no matter what the manuals say.

For the first time ever, after 28 vehicles, my perspective is short-term, 30K miles on my first-ever lease.

04WDPSeDaN

iTrader: (1)

If you're not taking apart the engine, you won't know what's going on. You stated a 99 Accord, keep in mind, the engines have changed since then. Most modern engines get the most amount of power from higher compression and or force induction, better intake and head(s) design. Back in 1999 there was no ethanol in the gasoline. Hell, back then you got 94 octane in NJ at almost all gas stations. You have to look at it in a simple way. Things have drastically changed since then. Most of those cars used cable throttle body, now every single car is drive by wire. Back then most honda/acuras used different intake sensors which are no longer used today. I appreciate your post, it was informative, unfortunately for today's way being of vehicles and gasoline use your post doesn't help.

If you are leasing a car, do whatever you want. At 30K what does it matter to the owner anyway when they trade up to another vehicle. If you are going to own this car for the long term, then it would be in your favor to use 91 or higher.

hddnav

Entirely possible. However, the average owner needs to make a judgment call between what's marketing and what's engineering. We need to decide whether we trust Honda Motor Corporation, with millions spent on R&D and engineering and decades of experience, versus the hearsay of "internet guru mechanics."

For the record, I'm not advocating that owners not use the recommended grade of gas, but I do think that it would be wise to understand what the pros and cons are of not following the manufacturer's recommendations (and yet not violating the requirements).

These are quotes from the 2013 TL Owner's Manual (3.7L engine), not mine. Plenty of cars have "recommended" premium, but not nearly as many have "required" premium. What's my opinion of putting regular into my TL? I'll probably have pinging and knocking at high-rpms, along with ECU retarded timing. In time, the premature detonation may possibly reduce engine longevity. I will also lose maybe 5% of my peak horsepower at those high rpms. However, it's also entirely possible that other parts of the car will fail long before the engine.

The way I see it, if I'm in the mode of taking care of my car (along the same lines as keeping it serviced according to the factory maintenance schedule and washing the car regularly), I would probably put in premium, if it's recommended. However, I'm not of the high-minded opinion that purchasing an Acura and using premium gas are automatically synonymous, especially when considering that Acura's true strength is bargain basement value luxury for the money.

I've owned enough cars that recommended premium gas to know that once the luster of the new car ownership wears off, these tiny costs that seem to have no return on investment become tiresome. My previous 2005 Subaru Outback XT had a turbo engine that "required premium" and actually saw premium gas it's entire lifetime. Our 2003 Highlander V6 recommended premium, but only had premium the first 50k miles. Now, the car has 150k miles and is still running strong, with no hint of pinging or knocking, even at high rpms. My previous VW Jetta VR6 also recommended premium (but who's to say if it truly "needed" premium). The point is that there is enough misinformation out there that owners really need to be educated about what's truly required, versus recommended.

ggesq

iTrader: (1)

The potential for knock, premature detonation, timing being retarded, ignition retard are all reasons why IMHO Acura has recommended premium for the TLX. I'd rather trust HMC R&D and their recommendations on fuel.

dzionny_dzionassi

Who are these guys, are they from this forum?
I strongly recommend, do not to talk to them anymore.
They are brainwashing you.

a35tl

There's one station near me that is selling regular for $2.29 and their premium is $3.23. Biggest spread I've ever seen in my life. Most stations in my area have regular priced around $2.27 and premium around $2.64. Average spreads are from $.37 - $.41 here. Was shocked to see the $.94 spread at the one station. I've been watching it for 2 or 3 weeks now and even though their regular has dropped some in price, their premium remains at $3.23.

clocks

I saw a small station today where the sign said "Plus" (not sure if that was mid-grade or premium) was $1.04 more than regular. I don't know what's going on in IL, but evidently the stations are starting to gauge premium buyers. I hope this isn't a growing trend. If the spread continues to increase I may drop down to mid-grade, as the car is leased anyway, and I'll only have it a few years.

crownr0yal

I've noticed that here in NC, where Regular is cheaper, Premium is more expensive. Cheapest I've seen so far for regular in my NC travels is 2.16 ... and premium was still 2.63 ... but where regular was 2.25 - 2.30 ... Premium was around 2.50. so weird.

04WDPSeDaN

iTrader: (1)

Knowledge is key.
2011 - engine knocking - Acura MDX Forum : Acura MDX SUV Forums

https://acurazine.com/forums/1g-2g-m...inging-786871/

2010 MDX experiencing pinging noise during slow acceleration - Acura MDX Forum : Acura MDX SUV Forums

There are countless threads about the pining issue with the MDX and ZDX. A lot of people were using regular which is a huge NO. Even with 93 octane some still pinged. After Acura released a re-flash update on the issue, it helped, however, customers were told to run the highest octane possible. Some TSX with the 2.4L also suffered pining issues. Again, this goes back to what I said. These engines are high compression, gasoline is no longer pure.
To see what happens to any engine with long term effects of regular gas just Google" Carbon build up" and view images. German vehicles suffer from it more, but the principle of what's affected is the same.

Colin

I'm not sure if I would compare anecdotal evidence citing the older J series motors with the newer direct fuel injected J series motors. However, as always, "fuel threads" are the best.

hddnav

Although we're ultimately always only talking about an extra 25 cents per gallon for premium, fuels threads are always inevitably tinged with strong opinions, because of our current culture's (in the US) tendency to use half-truths and hearsay to exploit the general public for the financial gain of a particular special interest.

"Since this expensive BMW needs premium gas, your Honda Fit will also run better with premium gas. Or your Toyota Prius, which you bought to save fuel costs in the first place. You know, garbage in, garbage out, right?"

I'll be the first to say, please give me an extra 0.2 liter of engine displacement, reduce the compression ratio to compensate, charge me $1000 more for the cost of the car up front, and get rid of the need for premium. I have no problem paying more upfront for better performance, but I don't like being nickeled and dimed.