Toyota Corolla

friendly_jacek · November 2002

RE:
"if anything, DO NOT ever use premium in your Corolla. If you do, premium will actually increase the carbon deposits in your engine and exhaust, because the Corolla engine (and any other 4-cylinder engine for that matter) don't change their timing ratio when you use a higher octane engine."

Hmmmm...
Do you have a reference for this statement?
Sounds rather dumb.

Actually, the VVT-i engine (1ZZ-FE) has a hefty compression ratio of 10.5:1 or so. Such compression usually requires a higher octane gas to prevent detonation. For this reason, the ignition timing is heavely modified in Corolla to accomodate 87 gas. Some people report measurably better milage with 91. I would not be surprised if HP also increases.
Did anybody do a dyno study on 1ZZ-FE with various fuels?

ultrarunner · November 2002

I have noticed that I always get more mpg when using 89 octane over 87. The highest mileage to date is 40.6 (2001 Coralla S with 4spd auto with 15,000 miles)

mpgman · November 2002

I suspect that there will be little difference between the manual and automatic unless one really opens it up in each gear with the manual.

canc · November 2002

First, let me say that your comments are justified, yet your opinions are not. Calling my statement "rather dumb" is uncalled for in these forums--not a very "friendly" statement at all, as your name would suggest. Please refrain yourself from making such statements in the future, for everyone's benefit here on Edmunds.com.

About your comments on the new Corolla engine, yes the compression ratio is very high, but like you said, "For this reason, the ignition timing is heavely modified in Corolla to accomodate 87 gas". In this respect, the Toyota V6 also is modified to accommodate 87 octane gas, yet the owner's manual recommends 91 octane for "improved performance". The Corolla engine, to my knowledge, does not have engine knock sensors like the V6 has, and therefore has no real means of distinguishing between octane differences in the gas. The V6 engine I was told would adapt itself to the kind of gas that was put in by changing its timing ratio. The 4-cylinder does not have this kind of technology. Perhaps due to the higher compression ratio the premium gas would not carbonize the engine as much, but I think it's safe nonetheless to assume that someone putting premium fuel in a Corolla is literally burning away money. In other words, the few extra miles you could get could not compensate for the higher price of premium, and possibly damage engine parts (carbon deposits, and catalytic converter).

jeprox · November 2002

i have to say that your comments about using premium unleaded will increase carbon deposits sounds strange. i have to agree though that using premium on corolla's are not needed and would be a waste of money.

as far as corolla's not having knock sensors, i think they do. i could be wrong though... but most new cars nowadays have knock sensors on them.

you are correct that toyota's v6 will take regular unleaded coz they have knock sensors BUT they recommend premium. just like my sienna's manual, it says ok with 87 octane but 91 octane is recommended. many people use regular just coz its cheaper but i personally believe that in the end when the engine gets older, it will affect the engine. since day one, i've been using 91 octane for my sienna. i bought it new, it recommends 91 octane and i spent over 30 grand on the van - i'm not about to get cheap on the gas!

i see people driving lexus with v8 that recommends 91 octane, yet the use 87 octane coz its cheaper. they can afford to buy a C$80,000 car but they cant afford to buy 91 octane gas!!

canc · November 2002

Perhaps a car with a much lower compression ratio might have carbon deposits, who knows. Maybe a mechanic here might want to explain this (don't look at me!).

I've also seen the same phenomenon at the pump, where they put regular in the Lexus. I don't understand that either. Why is it, however, that GM/Ford/Chrysler V6s don't say that they require premium, whereas Toyota does? Is it because the Toyota V6 is picky, and requires only the best gas? Even Honda touts that their new Accord's V6 still requires 87 octane, they say "due to better engine knock sensors". Maybe Toyota is recommending premium to save its owners expenses in the long run? Why, for example, should you put premium in your Sienna when the neighbour puts 87 octane fuel in his Windstar, and it runs fine like that?

nippononly · December 2002

a lot of the Toyota V-6's require premium in some applications, while the exact same engine in a different model will use 87, and this is because of differences in engine management systems, as a result of the fact that different models have different emphases.

I know you can use 87 in the Sienna, so that is a bad example. But several of the Lexus sedans will recommend premium, but will take 87 only with reduced performance. Some require it, and won't take 87, so you have to find out which you have.

It is not because some do not have knock sensors - all cars have knock sensors, it is just that some have less ability to retard timing or advance it for changes in octane.

In the case of a car like corolla, you may just be shortening your engine's life by putting in 91 when it is supposed to use 87, because you are creating a hotter and more powerful explosion in each detonation than the engine is designed for.

m3fan · December 2002

I have a bridge toll transponder that I need to attach to the windshield. I'd like to stick it above the rear-view mirror. However, there's that black dotted area on the windshield that blocks the sun I guess. I tried with my nail and it seems like it's durable stuff. Would I be able to stick the transponder there and not worry about the stuff coming off in case I want to remove the stickers?

Thanks.

jeprox · December 2002

pardon me, but what's a bridge toll transponder? those black dots are hard to remove and are there for a reason - i heard that they help keep your glass from fogging up or something like that.

m3fan · December 2002

Well, maybe it's not a "transponder" as such, but it's a little thing that we use around here to pay bridge toll without tokens or quarters. Basically, you go by a toll booth and it automatically takes cash out of your account and the gate opens.

It has two sticky things on it that glue the holder to the windshield. It has to be in clear view for it to register each time you cross the bridge. I'd like to put it on top of those black dots to make it less visible, but I'm worried they'll get damaged in case it needs to be removed. If so, I'll just stick it below the rear-view mirror.

friendly_jacek · December 2002

don't be so sensitive.
I apologize if you feel insulted.
I hate when misinformation is spread.
I never heard that premium fuel could cause carbon deposits. I would like to learn new things so please provide a reference to support this statement.
The only association of carbon and premium fuel I am aware of is that cars with carbon deposits require premium fuel to prevent knocking.

BTW, somebody stated above that:
"you may just be shortening your engine's life by putting in 91 when it is supposed to use 87, because you are creating a hotter and more powerful explosion in each detonation than the engine is designed for."
Acctually a fuel with a higher AKI (anti-knock index = octane rating) actually burns more SLOWLY than fuel with a lower AKI. This is because the fuel is less volatile and requires more heat input before it begins to ignite.
So, there is no "explosion", no "detonation" and no reasons to damage the engine.

Coming back to Corolla, the engine's computer system retards the ignition timing (reducing horsepower and fuel economy) to keep the engine from knocking while using 87 fuel.
People generally report increased fuel economy with 89 and 91 fuel in Corolla. To me, it clearly suggests that the engine changes timing in responce to better gas.
I have no proof however and thus this is only speculation.

fgf001 · December 2002

I believe I'll fill up with 89 octane next time to see for myself if there's any significant gains in mileage & performance. I'll post afterwards with the mileage and "seat of the pants dyno" report.

nwng · December 2002

try use velcro tape,thats what everyone uses for their toll transponder around here

lefttrun · December 2002

I'm a little confused by Toyota's bumper-to-bumper
warranty. Recently my corolla gets some dings on
a door and the top, and windshield was hit by a
small stone on highway, which caused a little
crack of half inch long. But when I went to the
Toyota dealer, they said both of these problems
were not covered by the bumper-to-bumper warranty.
Oh yes, there are several places where the paint
coat was scratched and rusted, they said that was
also not covered. Are these true or the dealer was
cheating?

anonymousposts · December 2002

That is normal wear and tear and is not a mechanical defect. Sounds like you should take your car to the insurance company and not the dealer.

My car recommends 87 but I've used premium since day 1 and I can tell a difference. The engine seems a little peppier if I use premium. If your engine is calibrated to run on premium it will make a difference, if it's not then there is no significant advantage to using a higher octane than the manufacturer recommends.

canc · December 2002

I don't have an actual Internet reference, but I believe this to be pure logic. Basically, if a car can't change its timing ratio, it doesn't give the gas enough time to fully ignite in the combustion chamber. The leftover unignited gas flows out of the exhaust unburned, creating with time carbon deposits. This is also why it would harm the catalytic converter.

lefttrun · December 2002

Thank you for your suggestion. I was not joking,
but I was ignorant about warranty and thought this
is a good place to learn. Now I know who shall
deal with my problems.

Since that warranty only covers mechanical defect,
and my Corolla doesn't have any of it (it's such
a good car), I'm a little regret having bought
the warranty. It's of no use and just waste of
money. (Am I ignorant again?)

jeprox · December 2002

those things you mentioned are not covered by bumper to bumper warranty! i dont think any manufacturer would cover those.

bumper to bumper basicaly means the parts in your car not related to everyday wear/tear. example: you bought your car for a week and for no reason, your front grill or headlights just fell off or your rear light assembly fell off - this would be covered under the bumper to bumper warranty.

read your manual and it explains what is bumper to bumper warranty and what it covers.

terceltom1 · December 2002

So what did you do to your Corolla to get it "calibrated" to run better on premium gas ???

nippononly · December 2002

exactly, the higher octane gas resists detonation at the moment that the car's timing expects it to detonate, so that when it DOES detonate, the explosion takes place at a different place on the piston's stroke, which over time can lead to increased wear on the engine internals.

terceltom: LOL! I was thinking the same thing! But he/she did say "no significant advantage", so maybe they do not consider the slight boost they feel is "significant".

Road damage and wear items are not covered by the bumper-to-bumper warranty, but if you paid for an extended warranty, you will be covered if things break, like power windows (expensive, covered for free), interior trim or buttons (annoying if you have to pay for them), other stuff like that. Not to mention the important expensive stuff, like the transmission and the engine.

So the extended warranty can be good for peace of mind.

fgf001 · December 2002

"My car recommends 87 but I've used premium since day 1 and I can tell a difference. The engine seems a little peppier if I use premium. If your engine is calibrated to run on premium it will make a difference, if it's not then there is no significant advantage to using a higher octane than the manufacturer recommends".

The above is an absolute contradiction of terms! Is the statement a joke and I missed the point?

Engine seems peppier- How would you know if you've never run regular gas in it?

If there's no significant advantage to running premium fuel, why are you doing it?

anonymousposts · December 2002

It is recommended that I run 91 octane but Honda says it will run on 87 octane. So what I meant to say is that if your car is recommended to run at 87 octane using premium will not make a difference but if your car can run on 87 octane but 91 octane is recommended then you will be able to tell a difference between the two.

I know it feels peppier because once on a trip we put 87 octane in it and could tell a difference in engine performance and fuel economy as opposed to using 91 octane. Other than that 1 time the car has ran on premium only.

fgf001 · December 2002

Ok, now I gotcha.

newtoy3 · December 2002

I'am looking to purchase a ce model the only options that are actually listed a toyota website basically only offer power door locks. Does anyone know if keyless remote entry can be added at the dealership?

friendly_jacek · December 2002

Not exatly. The major diffrence between gasoline and diesel engines is that gasoline IS NOT supposed to ignite spontaneously (detonate). It is supposed to ignite precisely when the spark plug fires. And using higher octane fuel provides for this even in the adverse enviroment (higher compression, carbon deposits, heat in the combustion chamber, etc).
Your arguments not only fail to convince me but also give me some ideas that the common knowledge about combustion engines is quite superficial around here.
Disclamer: I am not an engineer, far from it actually.

canc · December 2002

Yes, keyless entry can be added at the dealership. You can usually get it with the remote starter.

dudleyr · December 2002

So how many gallons are you using when you go 410 miles or 325? What mileage are you getting - "may get 29 mpg" seems kind of vague. Have you done the math, or are you just gauging by how many miles you go - which is incredibly innacurate.

friendly_jacek · December 2002

Boiler,
I drive mostly in city in my 2003 corolla s and the milage is very stable at ~27 mpg with only one exeption of 30.5 (very very light acceleration trial).
I now experiment with higher octane and will try synthetic oil like fgf did.
BTW, somebody reported periods of poorer fuel economy associated with strong H2S (rotten eggs) smell several weeks ago in one of the Corollas forums. I hope you don't have this problem.
Cheers

boilerman · December 2002

I always calculate the mileage from total miles driven by total gallons used to get my mileage. On each tank, it has been calculated within .1 of a gallon. So 410/12.2 350/12.2
and 325/12.1 would be very close comparisons. I also have had the strong "rotten egg smell" which Toyota service has told me is just in the gas which is BS . The 410 total mileage has been by far the best I have had.

nippononly · December 2002

well, I used to rebuild engines for spare $$, but I guess I don't know much...

if there is one thing I know, it is that running premium in an engine designed for 87, particularly one like the '03 corolla that is not designed to accomodate it, WILL lead to premature wear...

beyond that, I tend not to explain myself that well in writing, so that may be the weakness here...

alpha01 · December 2002

Note on fuel economy- in their test of the 2003 Corolla automatic, Consumer Reports lauded the vehicle for strong and efficient overall performance - at a combined 29MPG. That was the June 2002 issue, btw.

alpha

terceltom1 · December 2002

If your not an engineer why pretend to know more tnen the true engineers at Toyota and begin using the recomended oil weight and correct octane gasoline that they suggest for your automobile?

luckyk · December 2002

I've had my S since July. Very consistent 34-35 mpg in a mix of hwy and suburbs. Put some 91 octane in the 2nd and 4th tanks with only little difference. Hardly perceptible. All 87 octane since.

Lets see......11 gal tank. How do you put 12.1 or 12.2 in it without running out of gas. The most I've ever gotten was 385miles on a tank and that fill took just under 12 gal.

luckyk · December 2002

My S owner manual says 11 gal. Would have never assumed the tank sizes would be different.

And your calculations are right on. Must have been a lot of city driving with the a/c on for that tank.

friendly_jacek · December 2002

How about thinking outside the box.
As William Shakespeare wrote: "There are more things in heaven and earth, Terceltom, than are dreamed of in your Toyota owner manual."
Disclaimer: I am not an English literature professor, far from it actually ;-)

friendly_jacek · December 2002

My 2003 S owner manual says 13.2 gal. Would have never assumed the tank sizes would be different. What country are you from? Are we talking about US gal?

johnclineii · December 2002

What US gal? And how did women fit into THIS discussion?

(running and ducking....)

friendly_jacek · December 2002

A great reference on 1ZZ-FE can be found below.

It is dated 1998 and thus, no description of VVT-i nor plastic planum intake. One interesting point: the motor is most efficient at 3000 RPM. This illustrates possible MPG improvements with CVT.

http://www.matrixvibe.net/docs/1zzfe.pdf

luckyk · December 2002

I'm a knuckle head, or need to see the eye doc. My manual says 11 gal capacity, but that's Imp. Gal. It's 13.2 for good ole American measures. I appreciate the discussion. I may have never figured that out.

But this brings up a different question:
I still have over a gal of gas in the tank when the gauge hits "E". I've never put more than 12 gal in. I suppose this could be a good thing (never run out of gas). But I'll be monitoring more closely to see how many miles I can get from a tank at a conservative 33 mpg figure.

johnclineii · December 2002

Not necessarily a good idea. Running low on gas is not good for the fuel pump, which lives in the gas tank and is cooled by the gasoline. Far better to refuel early than late. Constantly running low on gasoline is the number one cause of fuel pump failures, and is why ex-rental cars, in particular, have high rates of fuel pump failure.

Just thought you might want to know.

Also, low fuel levels contribute to possible fuel line freeze ups in frigid climates.

coolguyky7 · December 2002

Perhaps the new Corolla is doing well with the younger crowed. Friday night I saw some young girls (no more than 18 years old each) in a white LE "b-boppin" to their loud music. Head shaking and body rocking was involved.

coolguyky7 · December 2002

Is it possible to buy clear projector headlamps (like in the 98 and newer Corolla) for a 93-97 generation Corolla?

vwmonsoon · December 2002

Does anyone know if the leather on the seats are real or synthetic? On the Protege5, the seating surface has real leather but other areas are trimmed with fake leather. I wonder if it's the same case for the Corolla...

lochlyn_deck · December 2002

Was wondering how the new Corolla handles in the snow. All the ones I have seen have Goodyear Integrity tires and from reading all the negative reviews on Tirerack.com, it sounds like the handling is disappointing. So is it just poor tires or is it the car?

backy · December 2002

The Corolla LE has REAL leather seating surfaces as an option. It is common for surfaces other than seating surfaces to be vinyl on all but luxury cars, although some low-end cars do at least cover the console arm rest, door inserts, shifter, and steering wheel (that is, every place you touch) in leather.

johnclineii · December 2002

These days even most luxury cars do NOT have wholly leather seats.

Then again, some cars have holey leather seats!

fgf001 · December 2002

Mind you I haven't even SEEN snow in more than 30 years but I would bet that better tires would make a world of difference. Most FWD cars are average or above in the snow but winter tires are critical. The Goodyear & Firestone tires that come as OEM equipment are meant for longevity, quiet ride, and so so performance across the board....which is what they deliver.

behhpp · December 2002

We had an ice/snowstorm here last week. The Corolla handled very well. I never had any problems slipping or spinning on the ice while other cars around me were having problems. I took it slow, drove in lower gears, turned off the overdrive. All of these things may have helped.

If I could get rid of the sulfur smell I would be a happy camper.

bloodclot · December 2002

Hi all, I'm new here and have a question. My wife and I have decided to buy a Carolla LE however the one that we test drove last night had the smell of "rotten eggs" when we put the heater on and it was more pronounced when the car was stopped. The salesman said that the smell will burn off after a few hundred miles. Huh!! I don't want the smell at all! Is that true? Will it simply "burn off"?

Also, my wife wants me to get the extended warranty. How much will it cost? What will it do for me? Is it worth it?

Thanks.

8u6hfd · December 2002

I wonder if the matrixvibe.net place has the permission from SAE to "publish" the tech paper on the internet?

Toyota Corolla

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