Lalin

During the first 10K miles with sports hybrid I used exclusively premium gasoline. For the past 1K miles I used regular.
The fuel consumption is pretty much identical. The price difference between them where I usually fill up is about $0.90 per gallon so it is a difference of about $16 per tank (per week).
I know that the engine is specified to run on premium; so was the case on my 2013 non hybrid. In that car I put 100K miles on regular and never had a problem or pinging.
Has any hybrid user experienced problems with regular fuel?

justnspace

iTrader: (1)

right, because modern ECU's will adjust timing for detonation.
The Hyrbid is no different, using a 3.0 V6 engine.

but the question is why? why use a lesser AKI fuel than what the car is designed for?

because you saved $16 a week?
perhaps you should buy something that doesnt require premium fuel?

mrgold35

Never understood the differences between the Acura and Honda versions of the same engine/powertrains with the same compression ratio that took different fuel types. Other manufactures figured out how to run an engine on 87-94 Octane with the disclaimer of "less power with less octane". I haven't found on the Acura website or in the owner's manual where you can use regular gas; but, the gas door has a sticker saying 87 Octane minimal. I always gas up at Sam's or Costco with around .40 - .45 cent price difference between reg and premium gas. It would seem the MDX hybrid should run on 87 octane first if you lean toward hybrid and 91-94 octane if you lean towards sport (keep mine in sport mode).

Sounds like another 87 -vs- 91 debate with evidence of issues with 87 octane as conman as a third nipple.

MCRacer

when we were looking at cars, the honda pilot was rated at a lower HP than the MDX. I suspect that the difference is honda specifies regular, acura premium and with the higher octane is able to use more spark advance and slightlyhigher HP. It's likely that the mdx will run fine on regular, it says premium is "recomended" not "required":. Nor does it have anything I could find in the owners manual about issues running regular. On a couple other cars I've got premium is "required" and there is information in the owners manual about what to do if regular is used, like limiting throttle and load until you can fill with premium.

So, what do I do? run premium. If I can't afford to run what's recomended I shouldn't have bought the car.

mrgold35

I would run anything from 87-94 Octane without any worries about causing problems in my MDX hybrid or RLX hybrid. I know I can squeeze a little more "sport" in +91 octane compared to the lower stuff and that is what I use. This advice is just me and me alone with my driving conditions, style, and environments.

Lalin

it is not a matter of affording.
the point is if the car for me runs as good and it gives me the same mpg, why bother with premium?

thoiboi

a cheaper car would also get you from point A to point B,

why bother with an Acura?




Same logic

skarface

You answered your own question. It's kind of pointless to put premium in these cars. If you don't notice any power/mpg difference you're throwing money down the toilet. With your savings of $16 a week, after the 6 year powertrain warranty is over you saved $5k. You could probably replace the engine for less than that on a 6 year old car. Otherwise, you're covered by the warranty even if you use 87 for the 6 years. Using premium is like an insurance policy with no benefits or payout if you don't notice a power/mpg difference.

bmoua15

Great point!

For myself I'll still be pumping 91

MCRacer

I'll agree that the performance difference between using 91 and 87 is likely not noticeable, around 10-15HP at the most. But to save $16/wk I'd need to drive LOTS of miles. We average about 27-28 with our hybrid. Using 25mpg as an easy calculation, 20 gallons takes us around 500+ miles. at 12K ish miles/year and 91 costing $0.20 /$030 more/gallon than 87 the cost is around $2/$3 /wk. or $100/$150yr. The difference won't even buy an extra cup of coffee/wk. For us to save $16/wk I'd need to drive 2K miles/wk or 100K/year! I'll stick with 91.

ESHBG

This is such a strange argument to me, as people will follow recommended maintenance, etc., to ensure that their vehicle runs well and for longevity but then when it comes to the recommended octane suddenly the engineers don't know what they are talking about.

Midwestuser1

It would be nice to know “why” they recommend premium as they don’t state why anywhere that I’ve seen.

MCRacer

Honda and acura use the same 3.5l engine. Honda is rated at 280hp using regular, acura 290 with premium recomended. So...... I suspect the premium recomendation is a result of some engine tuning taking advantage of higher octane fuel. Now 10hp is not likely to be noticeable except on the advertising brochures. It would be interestng to know what hp the acura will put out with regular? Is is 280 like the honda? or is it something less?

Some other mfg will give hp and torque numbers using regular and premium on engines designed to run on either and tuned to take advantage of the higher octane if used.

Boardmember

It’s a legit question and good discussion. Where I live, I have the option of 87, 89 or 93 octane. There’s about a $0.70/gal difference between 87 and 93. That exceeds the “incremental increased cost” discussions here.

I had run 87 in my 2018 for a couple (three maybe?) successive tanks of gas. I cannot say with any scientific certainty I could tell any difference at all. But my gut said it felt better with 93, so there...

i now now have a 2020 and it’s 93 all the way. I’m a tier 1 snob too.

Hey. The mpg on these things is super. It’s all incremental.

MCRacer

at $0.70 I'd be thinking about which to use as well. Here it is usually about a $0.20 sometimes $.030 difference between 87 and 91 even for tier 1 gas. Here we don't have 93 just 91. $0.70 is about the difference between 91 with ethanol and 91 non ethanol for the few places that have it.

Donn0128

2018 tech with just over 19,000 miles. Best recorded 27.58 using Costco premium. Last trip half premium, half regular returned 26.78. So given everything I suspect its a wash what grade of fuel you use. As I understand things the difference between Honda and Acura is the engine tune. Acura is tuned for a bit more performance

Boardmember

I’ve considered a full fill at 93, then at 50% top off at 87. Averages 90, so I’d theoretically not be able to wait until fully 50% empty. If I go below 50% or forget where I am in the rotation, I refill w 93.

nah. PITA.

93. Though I do wish we had 91 available.

It it begs the question: do I get the same incremental improvement (93 over 91) that 91 gets over 87?

MCRacer

probably not. If the engine isn't tuned to take advantage of the higher octane, you likely won't get any improvement. And since the engine is tuned for 91 octane, I'll guess not advantage to 93.

LakeErieMonster

While i don't have a hybrid, i can tell you that my 2015, 2017, 2019 and now 2020 MDX Tech's run just fine with regular. Currently I have a 2019 and my wife a 2020.



Your are correct that the HP is 280 with reg. (Pilot) and 290 with premium gas (MDX). Absolutely now worth the money. My dealer even fills up the car with regular when my cars were delivered new. The computers are easily capable of adjusting for whatever fuel is used. No harm on this car. There will be a slight increase in MPG with prem. but not close to justify the diff in cost per gal.

You'll be fine. Worry about something else. No need to spend an extra $1000.00 per year in prem. fuel unless you really want to.

LakeErieMonster

You are exactly right....

mrgold35

I don't what is different about Sam's Club fuel in Texas compared to New Mexico? I drove 4 1/2 hr from ABQ to Lubbock at around 26-27 mpg 220 miles at 80 mph (100 miles at 70 mph), fueled up in Lubbock (91), Abilene (91), and San Antonino (93) Sam's Club and barely making it right below 23 mpg. Even took a day trip from San Antonio to Corpus Christi @330 miles total and still avg just under 23 mpg. Once I fuel up again in ABQ, back to 25-27 mpgs. I get better mpgs at 5000-6500 feet in New Mexico compared to Texas. Don't mind the Texas gas prices since Sam's is under $2 per gal for the good stuff.

MCRacer

$1000/year would mean LOTS of driving. Here 91 is $0.20-$.0.30 /gallon more than 87. So at $.25/gallon, that's 4,000 gallon/year. now at 25mpg that's 100K miles/year. The difference for most people is more like $100-200/year. $2/$4 per week. Still not insignficant, but not outrageous either.

I do wonder why Acura doesn't either give two HP ratings, 87 and 91 octane like some others do, or another disclaimer. Also If I was towing with a MDX I would definitely use Premium. Under heavy load if the engine can take advantage of premium and give more spark advance and better performance, mileage and reduced chance of engine issues.

csmeance

ECU adjusts timing for lower octane fuel, but you will end up with lower MPG and damage to the catalysts due to less efficient burn and also increased carbon buildup esp on the intake valves due to EGR system. Taking a shortcut to save a few bucks now will end up costing more later when a cat fails and you have to dish out 1K for a new one, or when your MDX starts consuming oil because the oil control rings will be clogged with carbon, or spend money on walnut blasting to clean those intake valves.

jefferson88

Perhaps the thinner air at altitude means less wind resistance at those speeds? Probably insignificant even if it is the case.

Back in LA for the week and driving the same 75-80 mph to get to work (less people on the 405 these days) and seeing 28-30 mpg (indicated) on the 50 mile commute. Oddly that is better than the 26-28 mpg at 75 mph I was getting on the empty I-25 in New Mexico. I expect the increase is because I am always following/drafting off other cars here. Either way I am not complaining, this mileage is amazing to me for a 3 row SUV.

mrgold35

My frequent trips to Texas, Colorado, Arizona, Nevada, Utah, and California with 11 MDX to watch my son run Div I track was my main reason for wanting to upgrade to the hybrid. I was seeing 14-15 mpgs sometimes with the SoCal traffic that would sometimes cost me $85 to fill the tank. Haven't made many trips this year because of Covid other than to visit our daughter in San Antonio several times. Might not travel next year either if my Son's college track team cancels Spring Track in 2021 like they did this year.

Either way, I would still stick with 91-93 octane if I can get a touch more added performance. I can feel the hp gain driving in San Antonio/Corpus Christi with the 3.0L engine compared to 5000-6800 feet in ABQ/Santa Fe area. I would take 5-10 extra hp at 80 mph driving up a +7000 foot pass over saving a few bucks. Probably wouldn't make a difference hp/mpg wise if I lived in Florida with 87-89-91 octane.

bmoua15

Its a tough call but end of the day i want the best performance out of my cars so I'm going to end up pumping 91. Great feed back though

LakeErieMonster

In our area-Northern OH-prem. fuel is .60 to .90 more per gal. Today the station across the street from my office is 1.92 vs. 2.68 for 91. That's .76 swing to get less than 1/2 mile more per gallon. I drive 20-25K miles per year so yes, it's $1000+ per year for me and wasted money in my opinion.

If Honda thought that running reg. gas in this engine was a problem, they would say "required" and also "require" it for the Pilot which they do not.

To the guy who thinks that they are going to have to shoot walnuts at my intake manifolds, they better load up on walnuts shells because there are lots of Pilots and Odysseys out there with the same engine.

csmeance

Save money now, pay it with interest later buddy. If anything be smart and get a costco/sams club membership for cheaper gas that is pretty much the same at other places for less.

Out of curiosity, do you have access to pilot's ECU mapping vs MDX and can tell me fueling/timing differences to account for regular vs premium? Didn't think so....
Thankfully I do and the tables are different vs MDX and pilot. Same with oddy too even they use the "same engine" in your head. MDX 2014-2015 have the same bare bones short block as the newer pilots. Other than that different bearings, crank, rods and piston design. Heads appear to be different from part numbers too. THUS Motors are different and ECU software is different.

Perhaps you should consult an certified/licensed engineer or stop assuming. Honda dealers are buying walnut blasting tools after dealing with a bunch of dirty intake valves on the newer DI motors, at least 5 in my area have purchased them within the last year. BMW has a few of them due to the N54, N55 and N62 burning so much oil and coating the valves.

Thankfully BMW and other euro brands with DI experience have the walnuts in stock for you! Hope you don't get stuck on the side of the road. I post here to educate people willing to be educated and learn the truth from facts, not feelings or opinions. If you don't want to that's on you bud.

https://bmw335i.com/2019/05/09/how-t...rbon-cleaning/

csmeance

Some stations "cheat" and use 91 with a little bit more ethanol for premium 93 octane. Depends on who is blending and processing the fuel for the station. 93 is blended with a little more ethanol (still under 10%) to get a higher octane but since ethanol has about 30% less energy than gasoline 1:1. That means lower MPG because the car has to spray a little more fuel to get the same amount of output. For example cruising at 70 MPH the car may demand 50HP. With 93 octane "Pure" you can spray less fuel and rev less to get that 50 HP vs using a 91+ethanol =93. In that case the engine would be spraying a tiny bit more fuel and reving 50-100 RPM higher to achieve the same output. Add into this that the trans will have to keep the torque converter unlocked therefore reducing engine efficiency even more. Once the tq converter locks the engine is as efficient as it can be.

Some gas stations carry pure 93 octane and I've gotten about a 3MPG boost in my MDX running it vs the blended stuff on a long trip to VA from FL.

Lalin

So after 25+ replies the thread turned to be a debate whether regular fuel can or cannot damage the engine. My original question was if hybrid users experienced engine problems due to the use of regular fuel.
Apparently not as non of the hybrid users reported it but the question is still open.

csmeance

non-hybrid uses port injection vs direct so carbon buildup will not be as bad when running regular but still will occur more than with premium

MCRacer

If one is using the same quality of gas, don't see where 91 vs 87 will change carbon buildup on a port injected engine. Tier 1 91 vs. off grade 97, yes could be a difference but if one uses tier one 87 or tier one 91 don't have a understanding of why it would lead to more carbon buildup on a port injection engine.

csmeance

timing advance is cut back and leads to less complete burn. That means more soot in the exhaust, which means more crud though the EGR system and back to intake valves. Run a car on E85 and you'll be impressed with how internals will look.

LakeErieMonster

First of all, I only buy my gas at Costco as it is Tier I.

Second, you really need to relax. If Honda/Acura "required" premium, i would run it. They DO NOT. My warranty would be voided and the dealer would fill up the car with premium at delivery which they do not. I never keep a car past 50K miles anyway.

It's going to be OK....just a couple of deep breaths will do it...

ESHBG

Of course the dealer won't fill with premium, they are cutting costs. I would not use that as a baseline for anything.

LakeErieMonster

Wrong Kemosabe. That is exactly the baseline. If you think an Acura Dealer is going to jeopardize a $10M-20M franchise over 4 octane points, your nuts. You keep running prem. and I'll keep running regular. I know you need to justify that extra money you're giving to the oil companies but I will respectably pass.

Boardmember

Hey LakeE - you enjoy arguments, yes? Ha

i would suggest the dealerships are doing nothing other than saving money on the “full tank upon purchase” because we all agree that an occasional 87 (or plain poorer quality) fill up doesn’t cause immediate catastrophic damage. They assume most will follow guidelines at their next fueling. Supposition, of course.

if $1000/year is a reasonable calculation for someone and they think that’s too much, this is a free country. I think I’ve read some good opinion and some better facts. Someone try half bourbon/half diesel. You’re allowed. Let us know.

LakeErieMonster

Will take your suggestion under advisement.

BTW, I would never put good bourbon in my MDX. I buy and enjoy that along with other things with the money i save at the pump. Cheers!

ESHBG

See below, my thoughts as well.