muscleknight

With Ike knocking out refineries I was wondering if 93 isn't available could I use 87 octane and add in the octane booster you see in the auto parts stores?

mscav

Some octane boosters can ruin your O2 sensor and/or catalytic converter.

Audi Junkie

will do it for real, but what bother in a pinch? Any car sold in North America can run on 87 safely. It all depends on driving style anyway. My Mom could drive a car needing high octane on regs, you can too if needed.<ul><li><a href="http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&amp;Number=1239827&amp ;gonew=1#UNREAD">http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&amp;Number=1239827&amp ;gonew=1#UNREAD</a</li></ul>

wilson94t

Lower octane gas is going to run hotter, and potentially damage your rings. (yes I've replaced rings/engines on cars because people have done this before)

If you read the labels on the octane booster
bottle, many of them claim to increase octane and "power" by cleaning your fuel injectors.

This is not the same.

Octane rating gives a guide toward resistance to detonation. Any ability to detect knock and adjust engine timing is a condition where something bad has been detected and the electronics attempt to compensate while a bad condition exists. (ignition at the wrong time!)

I suppose it depends on how far you drive, but seriously, do the math. if you pay 20 cents more per gallon over the course of a year, how much more is that really?

Assuming two 14 gallon fill ups each week, this is $5.60. Surely you can find another aspect of your life where you can cut $5-6/week before you freak out about 93 octane costs. Stop drinking cola, save your teeth, your kidneys, and your car.

Assuming 50 weeks of 2x fill-ups per week (there are probably at least 2 weeks per year when this does not happen) we're talking $280. C'mon, does risking engine damage make any sense at all at this point?

cesarperezpala

I have 16' Q5, I use 98 octane as Audi manufacturer recommendation. After ask to Audi engine technicians, they say you can go down to 95 plus boost additive. That suggestion makes more expensive per galon, but it is the best choice for places where there is no premium gas to get. When travel, just keep some additives as backup , and engine will keep great at start and response.

For additives: Audi additives or STP additives

Audi_Machine2008

In Chicago 93 Octane gas is $1.00 some times $1.10 difference from 87 Octane per gallon, My Q7 has a 26 gallon gas tank so that $26.00 to $28.60 difference a full tank than using 87 Octane. At 13 miles per gallon that's a Big difference $$$.

Opinions please, what you guys think about using 87 Octane gas and adding required amount Lucas fuel treatment per full up instead of using 93 Octane?

acruxksa

This is a super old thread, but I'm betting if your Q7 was built in the last decade, it's got a knock sensor, which typically results in a small sentence in your owners manual that states that your vehicle "may operate on 87 octane fuel but at reduced performance" or something to that effect. Should you run 87 octane in your car designed for 91? probably not. Can you? YES.

This argument will undoubtedly result in dozens of posts from people stating that if you can't afford to use 91 or 93 or 100 octane in your expensive European luxury SUV, you shouldn't have purchased it. Or the old school dinosaurs who will tell you it will damage your engine etc. etc. etc. Fact is, most owners manuals "recommend" 91+ octane but do say you can use lower at a slightly reduced performance 5-10hp or so. Modern cars are very sophisticated and simply retard timing advance to reduce engine knock.

Let the FUD begin......................