Premium or Regular Unleaded?
 

Which gas do you put in? Is it worth paying the extra 70+ cents for premium, in the short and long term?

3,750 miles over 3.5 months, never once used premium, even dealer admitted they use regular, as it is only "recommended" not required. I'm averaging 27.2 mpg to date, calculated. No complaints, plenty of power, no pinging.

AFAIK, the car requires premium. That said, many have driven with regular gas without the car blowing up.

The short answer is that if you're not getting detonation (knock) using regular gas on your usual commute then you'll be fine. You'll get a bit reduced power.

What does it say on your filler door "required" or "recommended"?

Dealer uses regular because it is cheaper.

Here's the label on the gas door ....


https://cimg3.ibsrv.net/gimg/acurazi...1adc851ece.jpg

I ran the first 3000 miles on premium, switched to regular, and noticed no difference in fuel economy or on-the-road power.

Premium is ‘recommended’, not required. The same engine and transmission is used in the Accord, and that calls for regular. The Accord’s power is rated lower, so perhaps premium allows a bit more power at the top end with WOT. I did not notice any more power in daily use.

Learn something every day. The 2018's were "required". In that case, running premium will give you very little advantage.

However, if you are in higher altitudes (NM/CO for example) then 85 is "regular" and 89 is "premium". In that case, the 85 is OK as well.

I've been using regular with no issues.

Some will say that buying a luxury vehicle means you can afford to pay for premium. Yes I can afford it but I dont need the extra hp boost for city driving.

I have run tier 1 regular in mine since day one. I am averaging 25.2 MPG with nearly 13K miles on her. No knocks, no issues.

The RDX makes 272 HP at 6500 RPMs. I never run it at 6500.

Those that state..you bought a $$$ car, use $$$$ gas...total garbage....go by the manual....simple as that....if it has to have $$$ gas it would say REQUIRED......Enjoy the new RDX

The short answer is that you will benefit from Premium in your RDX. Whether you want to pay the additional cost is a personal decision.
Here is the best video explanation that I have found, and is commented on by couple of experts from Car and Driver and is only 5 minutes long.

DavidH

Horsemnure. Premium will not help a car that is designed for regular. You're just flushing money down the toilet.

The NSX is the only Acura model that requires premium. It is recommended in all other models. This has been true for many years.

The NSX requires 91 and recommends 93.
All others require 87 (not 85) and recommend 91.

I run regular Octane 87 and have for nearly 17k miles.. Have never had an issue and I still get great performance and over 24 mpg on average.

The '15 TLX I had required premium

2019 is design to run or can take advantage on premium..

I think that more cars are like that now. With the advanced engine management available, some cars so designed can take advantage of higher octane gas without having regular cause any problems.

I always use top tier gas, and I think that that is very important in DI engines.

Can you define "top tier gas"?

I'm not sure if you're referring to the current lineup, but the 4G TL owners manual and fuel cap states "Premium Fuel Only".

I've said this 100x in the past (with all of the wonderfully insightful fuel-octane threads :rolleyes:): Unless you live in an area where Premium fuel is way more expensive than regular, it's likely not going to cost much more in terms of cost-of-ownership to go with Premium. For example, here in Utah, the stepwise cost from regular to plus to premium is $0.15 each - so $0.30 for premium vs. regular. If you drive 15K miles a year and get 25MPG, you're looking at about 600 gallons a year. That's an extra $180.

$180 is $180, which would be great to save. But IMO, to best protect the engine from potential knock as well as get the most out of the engine, I'd go with premium. But that's just me. If the car were a lease and I was just using it for light duty commuting then regular might be the way to go. But I keep my cars forever and push the engine pretty hard so for me, premium is a no-brainer. It's also tuned for premium so I'm kind of locked in at this point. (I have a TL, not RDX).

Just noticed the OP said $0.70 more for premium :what: That might be a deal killer. That's $420 more per year. That starts to hurt.

Top tier™
https://www.toptiergas.com/

And it doesn’t necessarily cost more either.

Sometime it is cheaper. COSTCO gas in the US is Top Tier

As did the TSX and RL and IIRC, the old RDX

Agree with you Madd Dog..

Recommended. Not required. Taken right from the TLX owner's manual:
https://cimg2.ibsrv.net/gimg/acurazi...e2be435be3.jpg

Yeah and the manual also says that lower octane gasoline can cause knocking and pre-detonation. I guess if I'm leasing the car that's fine, but if I'm keeping the car for the long run I'd rather not be penny-wise and pound-foolish.

Test all the octanes and see for yourself, worse case you only wasted a few bucks on a tank of 93.
I felt a increase of responsiveness when I use 93 vs 87, no difference if I just cruise on the highway at steady speed. I use a bit over 20 gallons a week where I am just cruising at steady speed. Personally I am still debating if it is worth the extra cost. Most people here agree that 87 won't break your car, however, I do put in a bottle of fuel injection cleaner every few thousand miles since I don't have "top tier" gas station around. I have been driving this route for over 10 years and mostly going to the same gas station and never had car trouble.

If the price difference was $0.15 cents more than premium, then it would be no issue. Here in IL it's normal to see a difference of $1 per gallon on premium. Costco is about $0.60 to $0.70 more per gallon. Looks like I will most likely will be using regular once I get my RDX. In my current maxima, I have used nothing but premium.

Are we still bothering to say "unleaded"? It's gotta be at least 30 years since I saw leaded gasoline sold anywhere except near race tracks.

Do you think that the use of regular grade gas, over a period of time, can have anything to do with RDX's that go into limp mode during heavy acceleration? For me I bought a high performance car and for a couple of hundred bucks a year I'm not willing to give up one horsepower or foot pound of torque in the name of economy.

Thanks guys. I have many of the TopTier listed fuel suppliers in my area, however I have never seen signage that advertises/confirms that. Have your fuel stops had signage stating TopTier, or do you just go by the listed fuel suppliers on the TopTier website? Obviously, I have never looked this deeply into fuel beyond just the octane rating.

I dimly remember seeing a mention of Top Tier at a Shell station and I'm sure that other stations mention it as well but it certainly isn't in your face.

Me? While TopTier mostly gives you some guarantee of a standard, I'd rather get gas at a busy non-TopTier station (assuring fresher gas), that at a very slow TopTier station.

For example, neither Sheetz (a MD/VA/PA/OH/WV/NC chain) or Pilot (truck stops) are on the list, but I'd pick either one of those over some little mom-and-pop TopTier station that looks like it gets a customer a month.

I go by brand name. I have been using only top tier since my first DI engine in 2007, when there were only a few near me, like Shell. Then Mobil/exxon came on, and a Sinclair replaced a Gulf station, and finally Sunoco signed on. So now, practically every name brand has signed on. Costco is on, but BJs is not.

Too, as recognized above, a busy station is always better, so if your good stations are not top tier, throw in some Techron every few thousand. Keep the fuel system clean.

As long as youre not using 85 octane you will be fine.

Watch out!

Wawa is 92 instead of 93.

At least in Florida.....

This should be a poll, judging by the responses. I use premium. I don't see a need to go against the recommendation of the manufacturer.

I’ve tested this numerous times myself with premium recommend vehicles, I would suggest others do the same. This way you will not have to rely on what others have experienced. Fill a couple of tanks on premium and then a couple on regular. Track the mpg on both. Make notes on performance or even better, pick a long stretch of road and time your 0-60 or 0 to whatever. Have you experienced and improvement using premium? Great, then ask yourself if the improvement is worth the cost. If there was no improvement then ask yourself why you are paying more for no returns. I know what I have found with my vehicles. I use regular.

Great advice to folks! Thanks! I concur.

It's always fine to get others' opinions, just remember, "trust, but verify". Blindly following other's actions/opinions is never a good idea.

I can't disagree that 87 won't break the car, since Acura says it's "ok". However, keep in mind that knock usually isn't audible to the passenger. According to some mechanics, including Ericthecarguy (on Youtube), on a scale of 1-10, knock as high as a 7 won't be heard by the passenger. That's just his opinion and the scale isn't some official quantitative measurement. But if that's even close to correct, it tells you that potential engine damage or at least increased wear due to knock could be occurring.

Again, that's just a theory and not necessarily substantiated. And if I weren't keeping the car for very long I wouldn't be concerned. But if you're looking to push that RDX to 300K miles, I'd probably consider premium.