Premuim gas in vehicles ???

[Bottom Line]

I am car shopping...actually SUV shopping. I am looking at midsize SUV's...(used 2004-2005) Acura MDX, Honda Pilot, BMW X5. Also...If you have any feedback on these vechiles...please provide. I recently drove the MDX, and Acura recommends using Premium fuel. I asked the salesman about using Premuim...he said he drove an Acura TL...and just used regular unleaded gas. What are the effects of using premium vs. regular unleaded?

I had not planned on buying a different vehicle right now...but, it became necessary( due to a lot of needed repairs) to get rid of my 99 Jeep...so the hunt begins.

 

[Dave S]

My Camaro SS also calls for premium. But I have run it on regular many times. There is just a hint of detonation (spark knock) and some loss of power. Wiith todays computer controlled autos, you can run on regular on almost any car without worry. The computer is always "listening" for spark knock and when it hears it, it merely alters the timing curve by retarding the timing to avoid the knocking. If it makes you feel better, run it on plus (89 octane) which is just a few cents more then the 87 octane stuff.

 

[Dave S]

My Camaro SS also calls for premium. But I have run it on regular many times. There is just a hint of detonation (spark knock) and some loss of power. Wiith todays computer controlled autos, you can run on regular on almost any car that requires high octane without worry. The computer is always "listening" for spark knock and when it hears it, it merely alters the timing curve by retarding the timing to avoid the knocking. If it makes you feel better, run it on plus (89 octane) which is just a few cents more then the 87 octane stuff.

 

[Dave S]

Ooops was trying to edit my post and used the quote feature instead.

 

[goblue]

I recently drove the MDX, and Acura recommends using Premium fuel. I asked the salesman about using Premuim...he said he drove an Acura TL...and just used regular unleaded gas. What are the effects of using premium vs. regular unleaded?

I've been driving Acuras since 1985 or 86 whenever they first came out. There is no noticable difference when you switch to regular other than fuel mileage. I'm driving a 2006 TL Type S right now. When you put regular in it the mileage drops to 21MPG from 24. I had a 2004 TL with the standard engine in it. Samething...mileage would drop from 27 to 23. The fuel management system adjusts for the lower octance gasoline. It may cost more to run on regular than premium as the loss of MPG is greater than the price difference.

 

[RT 240SD]

Simple answer is they wouldn't spec it for the vehicle if it didn't have noticeable benefits. I've always run premium regardless, but I have never understood paying for higher end technology and not paying the little extra for decent fuel, especially considering you will get better mileage w/ the higher octance. Generally, premium fuel doesn't cost 10% more... but generally you will get close to 10% better mileage.

Then again, I run twin turbos so I give her the best moonshine I can find. I always aim for 93 or better. 91 in a pinch. I once got stuck in the middle of nowhere and had to go with 89 and babied it until I could cycle the fuel out. I felt guilty for being a bad father.

 

[Tallahassee240Sundeck]

I used to own a 2000 Honda Accord V6 and believe it or not, it would get better gas mileage on the cheap stuff. It surprised me, so in doing a little research, I came across others who experienced the same thing.

Basically, I believe it comes down to the specific car. Agree that if the manufacturer calls for 93, you should use it, but if it doesn't, do some testing between grades and see the difference.

Right now, our cheap stuff is about $2.76 a gallon, with the premium at $3.06, so the cost difference is about 10%. If you can get a 10% boost in gas mileage, go for it, if not, probably not worth the extra bucks... that is unless you start hearing knocking and such...

Also throw into the equation differences in manufacturing during different times of the year... I believe some areas call for a different blend summer v. winter. I don't know how that impacts mileage or performance.

 

[goblue]

A little off topic, but Crusader strongly recommends using regular vs. high test in their new 8.1s. The reps say right up front, you are wasting your money if you buy the high test. It gets back to the electronic fuel monitor software. Buy the higher octance only if regular is not available and then switch back to regular as soon as possible.

 

[spurofthemoment]

I am car shopping...actually SUV shopping. I am looking at midsize SUV's...(used 2004-2005) Acura MDX, Honda Pilot, BMW X5. Also...If you have any feedback on these vechiles...please provide. I recently drove the MDX, and Acura recommends using Premium fuel. I asked the salesman about using Premuim...he said he drove an Acura TL...and just used regular unleaded gas. What are the effects of using premium vs. regular unleaded?

I had not planned on buying a different vehicle right now...but, it became necessary( due to a lot of needed repairs) to get rid of my 99 Jeep...so the hunt begins.

Your vehicle is spec'd for a specific octane rating because of how it's engineered. Fuels with different octane ratings have different ignition points during the stroke of the piston. Your valves are timed to open/close in concert with the correct ignition points. When your put the wrong octane in any vehicle it can affect it's performance based on the previously mentioned points, not to mention sometimes cause an irritating knock. Now that being said, the computers in vehicles can sense the octane/fuel/air mixture and adjust most of the timings appropriately. But for peak performance you are going to have to go with what the manufacturer specifies. Oh, and conversely, putting higher octane in vehicles rated for lower octane doesn't provide any benefit.

 

[rondds]

use the lowest octane you vehicle will allow. i get a kick out of people who insist on putting 93 octane in their "baby" when it only calls for 87. i drove a 1981 toyota corolla to college that i HAD to use at least 91 in bc if i didnt, i had to pop the clutch to get it to shut off - what a POS!:smt043

i have a 2004 pilot and am very happy with it (my wife drives it and she loves it). i check mileage at ever fill-up and routinely get 18-20mpg in mixed driving (doesnt have a trip computer). if you were looking for a new vehicle, the pilot is due for a redesign (2009?), a'la the MDX - so you may get some sweet deals in the summer on leftover 2008s. personally i cant see spending the extra $10K on the MDX when it is essentially the same vehicle.

that being said, if i were looking for a new SUV now, i'd take a serious look at the mazda cx-9. motor trend SUV of the year and loved by every automotive mag i've read, including consumer reports.

 

[osd9]

Does that mean that my 1999 Isuzu Trooper is "out of grace" now.....:smt089...back in the day, Acura and Honda used to re-badge Isuzu SUVs

 

[Jaws]

I'm confused about the octane requirements as well.

I got into a lease on a 2004 Lexus RX330 with a 3.3 litre V6. It asked for regular gas. My dealer got me into a 2006 version two years ago, same vehicle and engine (no difference in the output, I think) but this one requires premium unleaded only. Same engine,..what gives? We live near the Lexus assembly plant and went for a factory tour one day. I asked about the octane requirements and they only said, obey your manual.

So I usually use premium but sometimes the mid-grade. My wife's car is an '06 Toyota Solara with the same 3.3 l. engine. It asks for regular, but I put in premium or mid grade because it's a keeper. I'm probably wasting my money on the expensive fuel.

James

 

[sbw1]

I'm confused about the octane requirements as well.

I got into a lease on a 2004 Lexus RX330 with a 3.3 litre V6. It asked for regular gas. My dealer got me into a 2006 version two years ago, same vehicle and engine (no difference in the output, I think) but this one requires premium unleaded only. Same engine,..what gives? We live near the Lexus assembly plant and went for a factory tour one day. I asked about the octane requirements and they only said, obey your manual.

So I usually use premium but sometimes the mid-grade. My wife's car is an '06 Toyota Solara with the same 3.3 l. engine. It asks for regular, but I put in premium or mid grade because it's a keeper. I'm probably wasting my money on the expensive fuel.

James

Can't speak to the specific engine in the Lexus, but compression has a lot to do with octane requirements. Audi uses 1.8 liter engines in many of its cars. The highest HP is currently 225 which they install in the TT. It's a high reving tiny engine that's really zippy at highway speeds. The same size engine is installed in VWs with a lot less HP. The high HP version has higher compression, stronger connecting rods, slightly different piston heads and runs on premium fuel. Both engines appear to be identical on the outside.

 

[Alex F]

In my opinion, 91 over 87 has the following pros:
1. With 91, engine runs cleaner and burns most of the fuel (only minor % goes to the exhaust). This is one of the main contributors to extend engine’s life. With 87, you don't get fuel burn as clean. Therefore, you waste more fuel and loose performance a little, but with today’s powerful engines and EFIs you don’t notice those small degradations.
2. Since most agree of us do agree that we get better mileage on 91 this simply means that you either pay extra now (at the pump) or you pay extra later (when you have to refill sooner). Thus, you don’t save anything for using 87. I’ve tested this with all my cars (SUVs and sedans) and the results were consistent. I also agree that every rule has exceptions where some of you may have experienced, although, it’s very rare.
3. Lastly, if you own your cars (I do) I think it’s better to use 91. I don’t think of my cars as “baby”, but I like to give them best I can (good fuel, good oil, etc.) and expect the same back. It usually works out just fine. If you lease your cars, I guess it really doesn’t make a difference if you don’t care what the car gets and just want to use it. As I said before, theoretically, you don’t save much at all.

Just my 2c.

Alex.

 

[sr360aft]

It is my understanding that the higher octane is just fuel with higher flash point not higher quality per se. No benefits other than ability to run in higher compression engines without risk of pre-ignition or detonation. It is also my understanding that the energy available in a lower octane is higher and, all else being equal, the lower the octane rating without ECU altered timing curve, the better the fuel economy. But if the ECU compensates for spark knock, power and economy suffers and higher octane fuel is needed

 

[rondds]

given the same engine in two different toyota products (lexus and solara), i'll bet it has to do with the on-board computer, not the engine. none of my cars require "hi-test" but if they did, i would use it. here in nj, the highest octane is approximately 20 cents more than the 87 stuff. assuming $2.80 for 87, you'd be paying about 7.2% more for 90+ octane. that means if you are getting 25mpg now, you'd need to be getting an additional 1.8MPG with the higher octane to justify the expenditure. not sure if that's going to happen, so i'll take the savings on the front end :thumbsup:

dominic, i remember the honda passport was a rebadged isuzu something-or-other! isnt isuzu part of fuji heavy industries (subaru)? how did honda and them get in bed together?

 

[billandamy]

I have never put anything other than premium unleaded from Mobil or other major gas company in any vehicles I have ever owned, from the classic cars to the sports cars to the suv's. I also use it in the snowmobiles, mowers and now I will with the boat.

Just force of habit, as I had read quite few times in articles that it was better for the engine, along with constant oil changes. Never had any engine problems ever related to moving parts, so I just stick with it.

 

[sbw1]

I have never put anything other than premium unleaded from Mobil or other major gas company in any vehicles I have ever owned, from the classic cars to the sports cars to the suv's. I also use it in the snowmobiles, mowers and now I will with the boat.
Just force of habit, as I had read quite few times in articles that it was better for the engine, along with constant oil changes. Never had any engine problems ever related to moving parts, so I just stick with it.

All gasoline is pretty much the same as is diesel. We live about 5 miles away from a major fuel storage depot. It is supplied by a single pipe line that comes up from the South, maybe in Mississippi or Lousiana. Anyway, that pipeline delivers diesel on one day and gasoline on alternate days. Dye markers are put into the line at the refinery so the various retailers know what fuel is theirs and it gets pumped into the proper storage tank at the terminal. So, every retailer is getting the same fuel which obviously has a little gas in the diesel and vice versa. At the storage tanks here, small amounts of detergents and other additives are dumped into the stew so Mobil can say it's Mobil and BP can say it's BP, etc. But, even the additives are pretty much the same. To make e10, the delivery trucks add some alcohol to their tanks before filling up with gas from the Mobil storage tank or BP storage tank, or whatever. There is no reason to pay a premium for a branded fuel for autos. I would pay a premium for Valvetech at a marina. In that case you are buying stabilizers, biocides and other lubricants that justify some additional price. Those additives are added at the marina. However, the underlying product is identical to other retail products for autos.

As far as frequent oil changes, I think that is also overblown. I drive about 25,000 miles per year and change my oil when the change oil lite comes on usually around 8,000 miles. Never had any engine problems. My wife drives about 7,000 miles a year and changes the oil once a year which is what the Audi manual says. Never had any engine problems either. I change the oil on my boat according to the owner's manual and have never had any problems with boat engines either. I think it's pretty interesting that people feel the need to do so much more than is recommended by the experts. When you get right down to it, it's really just a waste of money. I'd rather buy more fuel than more oil.

 

[rondds]

i agree with sbw1. follow the manufacturer's recommendations and you are doing all you can to prolong the life of your engine. most service schedules say 7500 miles for regular oil. synthetics allow for greater distances. i am a fool with oil changes on the cars however. 3mos or 3K miles, whichever comes LATER (not first). in my case, the three months comes later, as i'll routinely put closer to 4K miles in a 3 month period with both vehicles.

as for the boat, i change the engine and genset oil every fall. i have never put anything more than 50 hours on any boat, so i am well within the manufacturer's recommended schedule. now, my lawn equipment - that's another story! maybe every other fall. i just changed the oil on my craftsman lawn tractor after 2 years, and i got out the FULL 2 quarts and it was still amber in color (not black). that is after two years of mowing close to an acre once a week btwn april and october. which reminds me - the push mower, chipper/shredder and snowblower are due too :smt013

my subaru manual states that there is no need to ever change the tranny oil filter unless it is physically damaged. the car now has 92K miles and i have changed the filter and fluid twice. incidentally, the manual says INSPECT the ATF but does not call for a change unless you drive extremely or tow. i do neither. when i changed it this weekend for the second time, it was pretty black/brown, as opposed to the nice ruby red color. that is a recommendation, i think, that leaves a bit too much room for negligence.

obviously all these schedules are subject to interpretation, but it is always better to err on the side of caution! it is cheap insurance.

 

[wkearney99]

In my opinion, 91 over 87 has the following pros:
1. With 91, engine runs cleaner and burns most of the fuel (only minor % goes to the exhaust). This is one of the main contributors to extend engine’s life. With 87, you don't get fuel burn as clean. Therefore, you waste more fuel and loose performance a little, but with today’s powerful engines and EFIs you don’t notice those small degradations.
2. Since most agree of us do agree that we get better mileage on 91 this simply means that you either pay extra now (at the pump) or you pay extra later (when you have to refill sooner). Thus, you don’t save anything for using 87. I’ve tested this with all my cars (SUVs and sedans) and the results were consistent. I also agree that every rule has exceptions where some of you may have experienced, although, it’s very rare.
Lastly, if you own your cars (I do) I think it’s better to use 91. I don’t think of my cars as “baby”, but I like to give them best I can (good fuel, good oil, etc.) and expect the same back.

This is wrong, wrong, wrong. Using higher octane rating WILL NOT do *ANYTHING* to improve mileage or efficiency of burn unless the engine REQUIRES it. Although results may mislead you if you're dealing wiht an engine that's out of tune or inefficient to begin with.

You're completely wasting your money if you think putting premium will somehow "be better" for an engine that doesn't require it. Now, there may be some factors like additives (detergents and such) that may be found in given brand's premium blend that's not in the loca cheap place's regular. But even that's unlikely given today's fuel formulations.

It's just as true that changing your oil more frequently will do more to prolong the life of the engine than spending excessively on fancier oils. It had more to do with the changing of the filter than anything else.

If it makes you feel better to believe the myths, then fine, but don't go spreading that nonsense to others. It just isn't true.