spinedoc777

I read that Acura's require premium. My sales guy said he advises customers, and in his own car uses Plus (middle grade) with no issues. This is what I liked about my previous Genesis, I could put regular in it all day long. Can I scrimp a bit, or should I make sure I put in premium all the time?

nist7

https://acurazine.com/forums/third-g...x-gasp-976228/

Basic factual summary:
Acura only requires premium for the NSX.
Acura recommends 91 octane for the RDX for optimal performance.
Less than 87 octane can lead to engine damage in the RDX. (like who does this anyway...lol)

AAA has done a study and showed that the % increase in premium gas does not translate to a proportional increase in MPG/HP. On a pure mathematical basis of dollar per MPG/HP, premium/mid grade is not worth the additional cost.

Up to each driver to decide if it is worth it to get mid or premium gas.

87 octane from a top tier gas station is perfectly fine for the RDX. But others want to maximize mpg/hp at a higher proportional cost and always go for premium. No wrong answer either way. But some people may feel very strongly about their personal decision one way or the other.

Medjai

I've always put Premium on my cars (Acura and BMW) as "recommended". I've heard other people using Plus with no issues and read some Article about no difference between using Plus and Premium, but my OCD doesn't let me do that.

I think you'll be fine with Plus.

spinedoc777

Yeah I feel like Plus is hedging my bet a little. I can afford the extra $80 or so per month, but hey if it's free money. Well with Plus I suppose it's more like $40 or so every month.

nist7

If you have some time, this is a nice read: https://newsroom.aaa.com/2017/12/don...s-worth-price/

AAA actually parsed out the language and there is a difference between "requirement" and "recommended."

It certainly wasn't what I expected as I too would always go for what is "recommended" but the data appears to point otherwise.

In a parallel example, the NSX recommends 93 octane (which is not ubiquitous or easily obtained in certain cities/areas) and requires 91 octane. Whereas the RDX recommends 91 octane and requires at least 87 octane.

jesser916

I'm thinking about using Premium 91 (highest in CA) for the first 1k miles then switching over to 87 (regular grade).

Monster_HK

since I don't drive much, I live in NYC and take bus to work. I drive only during weekend, holiday and vocation. It is about 500 miles a month. The cost difference between premium and plus for 500 miles a month is probably $10 a month, so I go for premium as recommended.

securityguy

Why? You gain nothing by doing this.

jesser916

during break-in period. Probably won't make a difference but that's what I was thinking about doing.

Yotrek

Save money?

securityguy

You totally missed the point of the comment @Yotrek !!! Why use 91 for the first 1K miles and then switch to 87??? What's the purpose of using 91 at all in this instance? Breaking in an engine with 91 will be no different than breaking it in with 87. You get it now?

russianDude

Another gas thread...... Listening to advices from a sales guy?

Yotrek

SebringSilver

Midnight Mystery

Fill her up with distilled water or rubbing alcohol!

Midnight Mystery

Better yet, use 10w50 conventional oil, no one uses that stuff anymore so it's cheap as hell, and makes this cool blue smoke when you rev!

skarface

Since you're not supposed to give the engine full throttle during the break-in period (600 miles) per Acura, I wonder if using 87 would actually be better? The engine would retard itself and shift sooner so you couldn't get that high up in the revs. Cheap Insurance! Cheap gas and you protect the engine from getting up to redline haha.

securityguy

jesser916

yea I wasn't sure. I was just thinking about it. I'm still on my first gas tank from the dealer. Thanks for the advice!

russianDude

jesser916

Yes 'Recommended' not 'Required'.

What are you going to with optimal power? Race it?

Cost isn't an issue man. Go have some coffee and have a good day lol

nist7

Look at the AAA study. In regular driving they saw essentially no difference with usable power at 91 octane. Under WOT, the performance car (Mustang) saw a small % increase but the much higher increase in cost of the fuel means mathematically it is not a proportional increase/value-proposition.

skarface

Honda makes it easy for us by having a very similar 2.0L engine with 10 AT supplied in their other vehicles. Look at the recommendation for 87 in those vehicles and the quoted power rating and that's your answer on what you're losing by not using 91. The tuning companies already showed that the Accord put out a few more HP stock just by using 91. Again, this is all just marketing by Acura to make people feel like they are driving a special luxury car and can quote slightly higher power figures to differentiate themselves from Honda since they are testing the vehicle with 91 vs 87 in the Hondas. Whether the HP bump for the added fuel cost is worth it is up to you. The test below was done with 93 vs 87 octane fuel.

http://www.ktuner.com/dyno/AccordX/2L/93vs87Stock.png

russianDude

FrankZZR

russianDude

Yotrek

russianDude

russianDude

securityguy

Finally something we both can agree on

Cuzz

Sorry to be bumping some of these old threads, but I just recently added the RDX to my list and am playing catch-up. Since I tend to use just about 1000 gallons of fuel and get 24 mpg combined in my current daily driver, stepping up to premium will cost an extra $500/yr for gas. I expect to get 22/23 mpg in the RDX so I am hoping to use regular gas right from the start.

russianDude

Hmn, at my costco premium is 30 cents more, which is like $300/yr. I will use premium to get the most performance and cleaner burn.

Yotrek

This C/P
“No matter what you've heard, premium-grade gasoline won't do more to clean deposits from your fuel injectors or other parts of the fuel system because today's regular gas contains the same detergent additives. The main difference with premiumis its octane rating — 91 or higher compared with 87 for regular octane”

russianDude

Manual recommends 91 octane. With average 15k miles per year its $200 more per year. I dont care if its $200 more per year

Yotrek

Yes you’re absolutely correct, stick with 91 sounds good to me, only for folks who’s thinking using less recommend octane which is 87 min., that this explanation is for...

russianDude

I am sick of these debates and conspiracy theories about why Honda recommends premium and supposedly its not needed and blah blah... I really dont care, I can pay $300 more per year and not notice it

Madd Dog

My butt dyno says that 91 runs smoother than 87, so that is what I use.

Dereileak

Ditto, higher octane the less the car will retard the timing and lower boost because of pre-detonations, what’s $300 a year anyways nowadays 😁

Yotrek

Maybe cost more than $300 that you pay from where you are, how about other states or country? where it is clearly nothing wrong using 87 as stated and will not void warranty..just the thought..

russianDude

Depends on gas stations, I’ve seen some charge 60-70 cent more for premium. I always get gas at costco, and its around 30cent more for premium (93) all year round.
and costco is top tier gas.