gas grade?

[45beast]

Anyone try putting 89 or midgrade in their fx45? If so...everything normal?

 

[jdTrader]

thread moved from wheels forum.

 

[shadow191]

It will work. But your power will be down since the engine will pull timing. As the weather gets hotter, it will pull more timing because of knock. I've done it before on my 35 here and there if the gas station was out of premium, etc. There is a noticible difference. Especially in part throttle acceleration under load. You will feel the engine stutter a little bit as timing gets pulled due to knock.

So if you have to do it, go ahead once in a while. If you're doing it to save money, you won't really save that much and the loss in performance just isn't worth it.

 

[la_fx35]

^ :plus1:

 

[matrixx860]

I've only ever used premium.


Sent from my iPhone

 

[Visceral]

I'm going to go ahead and pretend like I know something and go ahead and say you should always use whatever gas the manufacture recommends...not because a higher grade is innately better per say, but because that is what the engine is tuned for. Higher grade gas has less combustible, which means more pressure builds before the spark plug ignites it, which means better piston travel. Using lower grade will likely translate into premature explosions, which is probably the "knock" shadow191 was referring to. Some manufactures actually prefer you do not use premium, and using premium in those cases could be equally bad for your car.

 

[flyingcolonel]

It's amazing how many folks will chance a major problem to save a few immediate bucks (but spend 'way more in the long run) with no knowledge of the physics. There's a lot of brain trust in the vehicle manufacturers' stable - why not just follow the recommendations in your owners' manual? And, for the record, I'm an engineer. PM me if you want to debate this.

 

[blackfx]

I have always used mid grade 89 in my 35. Never had any problems so far. Granted, going from regular 87 to the 89 I saw a large increase in mileage of maybe 1-1.5 mpg.

 

[shadow191]

Here's the thing, it won't cause any "problems". The knock sensors will pull timing and reduce power. So power will be down with lower grade gasoline. But you can do it forever and your car won't blow up. Lower grade gas will also result in lower mileage unless you drive like a grandma all the time. When the engine pulls timing, it reduces efficiency so you will get lower mpg. I'm not sure if it would be 1-1.5mpg though. I track mpg pretty regularly and running regular was usually good for a loss of .5mpg or so and that's compared to premium.

 

[Squishymedic]

93 octane here and once in a while I use this:

My neighbor's brother is the area distributor of BG...this stuff is incredible...they have all manner of additives and whatnot

---------- Post added at 10:39 AM ---------- Previous post was at 10:04 AM ----------

Also, for ANY of your small engines use barely a shot glass of this per tank

If the engine is "hunting"at all,,this stuff will straighten it out.