So my boss put 87 octane in his CX-7 Turbo

[Brigadier]

By mistake. His turbo'ed CX-7 requires 92 octane gas. He left his head in the passenger seat when he was filling up.

There is a gas station about 18 miles away that sells Trick Unleaded 101 octane gas. I told him to drive there and top off to raise his octane back up. He has burnt thru 3-4 gallons of the 87.

He doesn't want to pay the $$ for the Trick, and instead just wants to go to the auto parts store and buy an octane booster. I told him none of those will raise the octane level that much.

Am I wrong? Are there some that will work for him?

TIA

 

[440Magnum]

I'd tell him to keep his foot out of it until its half full, then just top off with ordinary premium. The engine computer and knock sensors should protect him from his own absent-mindedness.

Parts store octane boosters will help a little. But he doesn't WANT to use the kind that actually work well (the ones with MMT) because like lead, MMT poisons O2 sensors and catcons. Not as fast as lead, but it still does.

 

[GROUCHO MARX]

He doesn't want to pay the bucks for the trick gas? Why did he buy a car that needs premium gas in the first place?

 

[Brigadier]

Yeah, funny how people are about things, right?

Originally Posted By: GROUCHO MARX
He doesn't want to pay the bucks for the trick gas? Why did he buy a car that needs premium gas in the first place?

 

[Brigadier]

Him keeping his foot out of it would be a small miracle.

I guess there is a 'safe mode' the computer may trip on his engine, and I think it requires a trip to the dealer to reset. He wants to avoid that. That is why I believe the Trick gas is the best option.

Originally Posted By: 440Magnum
I'd tell him to keep his foot out of it until its half full, then just top off with ordinary premium. The engine computer and knock sensors should protect him from his own absent-mindedness.

Parts store octane boosters will help a little. But he doesn't WANT to use the kind that actually work well (the ones with MMT) because like lead, MMT poisons O2 sensors and catcons. Not as fast as lead, but it still does.

 

[stephen9666]

Originally Posted By: Brigadier
Him keeping his foot out of it would be a small miracle.

I guess there is a 'safe mode' the computer may trip on his engine, and I think it requires a trip to the dealer to reset. He wants to avoid that. That is why I believe the Trick gas is the best option.


Unless there's a problem that causes the MIL to illuminate (which I seriously doubt this will cause), then I don't see how a trip to the dealer will be required.

The knock sensors and computer are constantly adjusting the timing based on a variety of inputs.

I don't see how there will be a problem, but I will admit I'm not familiar with the specifics of that model.

 

[dparm]

It will probably not be an issue. I've had CX-7 rentals and I guarantee you they were not putting 87 in there...drove just fine. We have knock sensors for a reason; if it were the higher-output Mazdaspeed3 version then I might be more concerned.

 

[NHGUY]

Parts stores octane boosters raise octane in "points", real old boosters (the old 104+ and the old "Outlaw") would raise octane in "number".Points means less than one number (like .1,.2,.3...) a number means a whole number (1,2,3,4.....).So putting cheapy charley booster in 87 octane fuel would probably give 87.2 not worth it.

 

[SLCraig]

Just refill with premium when you can.
Cars arent stupid anymore.
When I bought my 02 Maxima the guy who owned it had never once put premium in it (requires premium) when I started running premium the car definitely came back to life and pulled how it should have.

To my knowledge years of 87 octane did no real harm because the car ran great for me up until I sold it.

 

[Brigadier]

He says he is going to top off with the Trick 101 on the way home tonight. I believe this is the smartest move, ESPECIALLY given his driving habits.

 

[cutter]

Why care, it's your boss.

 

[Brigadier]

Yeah, THAT'S really mature. Good grief.

Originally Posted By: cutter
Why care, it's your boss.

 

[Brons2]

The regular unleaded won't hurt the car with all the modern electronics, it may even get better mileage. On the downside, power is going to be down.

There's a number of people with the Saab low pressure turbos that get 35+ mpg on the regular, I have seen posts here about it. The car requires midgrade, I believe.

On many of the turbo cars that have come out the last few years, there have been separate HP ratings for 87 and 92 octane.

anyway...carry on...

 

[2004tdigls]

it will run ok beacuse the knock sensors will tell the ecu to pull back (retard) the ingition timing and the fuel/air ratio will end up being slightly richer to avoid piston killing detonation and pre-ignition

this all leads to poorer fuel economy and (over the long term) spark plug fowling

if he uses premimum fuel the fuel economy may be noticeably better

 

[Ken2]

I've got my eye on a Mazda for the future, but for now...

...I ran my Volvo turbo which "required" 91 octane or better on 87 for about 150,000 miles. It has continued to run great. I used 91 or 92 for highway trips in the mountains for that bit more power. I any difference in gas mileage just about equaled out the difference in price. As said above, the knock sensors and the rest of the electronics are always adjusting things, anyway.

 

[mechtech2]

It has to knock for the KS to go off.
So there IS knocking that should not be there.
This can't be good, esp long term.
And of course, power and economy will be down with 87.

KSs do not raise spark timing, they can only lower it.
In other words, you have a spark table , and it takes some away when needed [lots of times when NOT needed!].
I prefer to use the correct octane, when the KS does not go off at all.
On my car Ford ZX2], I disconnected the KS - it is safe to do so on some cars. This eliminated the random unnecessary spark pull and it runs better all around.

For your boss:
It will take a few tanks to get up to 92 again. [Unless he runs it dry then fills it.]
But he should be OK for this one time event.

 

[raytseng]

Originally Posted By: Brigadier
Yeah, THAT'S really mature. Good grief.

Originally Posted By: cutter
Why care, it's your boss.


well, take out the factor of the boss part, and the comment still stands.

If someone doesn't want your advice, or doesn't care one way or another, then save your breath and energy mind your own business. Plenty of other people who do want your advice or help.

Nobody likes the octane nazi or oilchange nazi telling you how you should maintain your car; same as those who lord it over you and complain from the passenger seat to use Regular even if you want to use Premium. It's basically another form of back-seat driving.

If they want your opinion then give it; if they don't, move along with your life.


It's actually a sign of maturity to be able to hold your tongue and not to tell people how to drive or how to maintain their car, or live their life; unless they actually are asking for your opinion.

 

[Spazdog]

The DISI turbo will be less likely to knock because of the direct injection. But I bet the ECU is still pulling back the ignition timing and he probably has more soot in the tailpipe than the average 'Speed3 or 'Speed6 on premium does

Just remembered. The CX-7i has the regular 2.5 MZR. Not the DISI. 87 will not bother it