I usually use 94 octane when I plan to go in boost but I do lots of highway miles lately and was wondering if I am just wasting my money.

Would 87octane work for cruising on the highway?

87octane = $5.06 per gallon
94octane = $5.59 per gallon

 

if u have Turbo, I suggest u stick with higher octane, you can try to stay off boost, but if go on boost by mistake ... a knock might destroy ur engine

 

I agree.

If it was NA you could do it, but a Turbo is asking for trouble.

 

Alright.

I am glad to hear I have not been wasting money.

 

On a turbo ? You might as well put in the order for a new engine now.

 

yeah i wuld stick with the good stuff for that turbo!!! 50 cents a gallon is alot cheaper than a new motor/turbo

 

Keep in mind that a turbo is only relevant when in boost.

I drove my car with no engine management for 3weeks and it drove like stock as long as I stayed out of boost.

 

I'm a proponent of 87 in stock NA cars, but in a turbo application I would definitely stick with at least 91.

 

Please explain why a turbo makes any difference than N/A while crusing (not in boost)

 

Marc_GS... Your location is Canada's Capital?!

turborx8 and I suggest you check out the Ottawa Mazda Club... We're looking to add more RX8's as we're over-run with 3's lol.

 

Ok, let me get this right, you have a turbo, and you want to run 87, ok, at least you asked if it was ok, but it seems your mind is already made up about the subject. So why even post? But the real kicker is you admited to running your boosted 8 with no EM... for three weeks. Nice.

 

Notice the OP's words. He was not in boost.

when u're not in boost, Turbo is just a exhaust restriction, nothing more.

 

I see his words very clearly. The difference is he CAN go into boost. I had a turbo, I know how easy it is to get there, hell I would go into boost with the cruse set; all it takes is a hill.

 

^^^

Never use cruise control up hill with a turbo car. Big waist of gas.

 

This is his choice. If he truly knows how to stay off boost, and remembers that with 87 octane he must drive it like it like grandma (cruise control at a steady 70mph will work), then I do not see a problem. There is a risk, but for pure highway, and being aware of the octane you have in it, it will work. Just remember not to boost at all to be 100% safe. Enjoy!!!

 

I actually came out to the Rona a few weeks ago for the "pre-meet". I had the Ti gray that you may or may not have noticed. I had other engagements so I couldn't stick around for long.

Dan, I don't have a detailed technical explanation for why it would be bad to run 87 off boost. It sounds like it would be fine BUT say you were to forget for a moment and get into boost while leaving a stop light. I know you specified highway use, but there's always the odd stop light, stop sign, etc. Would that damage the engine? You've got a really nice and fairly unique (at least around here) machine, and I would really hate to see anything bad happen to it.

 

i would use 89 for highway and daily commute?

 

I'm a big advocate of 87 octane but would keep away from it with a turbo, unless you don't mind a blown Apex seal.

 

You guys are forgetting that I have a boost controller.

 

87 oct and 0 boost ftw.. but do you feel lucky? punk?


beers

 

A boost controller can't reduce boost.
You would need to unhook your wastegate actuator to do that.

I don't know what kind of highway driving you do, but I spend more time in boost on the highway than I do in daily driving!

You want to go to this extraordinary step just to save yourself $3 per tank?

You do realize that you would have to continue this behavior for a thousand tanks of gas before it would pay for a rebuilt motor, right?

 

Don't Don't Don't
You have turbo car. You do not wanna put 87 octane in your car.

 

That's poppycock! everybody knows including John Candy that the Capital of Canada and therefore centre of the universe is Toronto. Leaf rocks!
Why turbo if you cannot pay for the high octane?

 

I never said I could not afford 94 octane.

I was simply concerned that I was wasting money on it since I am never in boost on the highway.