Mazda 6 Forums banner

1 - 20 of 25 Posts

·
Registered
Joined
·
701 Posts
Discussion Starter #1
After experiencing a slight surging issue at low RPM's (1500-2600 3rd, 4th, 5th Gear), I went to the dealer to have a look. The Tech Could replicate the problem but found no problems. They checked TSB's, and called the Mazda Tech line. Nothing.

One of the techs said this is not the first time a MTX V6 owner has complained about this exact problem. He recommended that i try going to 89 Octane, as 87 might be tripping the Knock-Sensor.

So I didn't have a mental "Seat of the pants, or Butt Dyno" influence, I devised a Plan with the Wife.

We would take 6 weeks. 2 straight weeks per Fuel Grade.

So here are the results of the abovetest:

87: Car Runs OK, no crisp, but OK. Slight surge @ low RPM (See above), and good high RPM Performance.

89: Car runs much better. Better Throttle response, low end power seems to be better, as does the smoothness of the motor. MPG is identicle to 87. I expect the car to get 430-450 per tank.

93: Premium a complete waste of money in the 6. It didn't feel any different than 89 Octane, Gas Mileage reduced by 3 mpg or so. I eneded up with about 350-370 per tank both weeks.

I figure that for $1.50 more per fill-up is worth it.


BTW: I read on the forum before I tried this, that using a higher octane will void your warranty. If you read the manual it states a "Minimum" of 87, not ONLY 87.
 

·
Registered
Joined
·
1,708 Posts
What type of gas are you buying? One brand? Cheapest you can find?

Could the gas marked as 87 be below 87?

If the 87 is a little low (say - really 86) it might cause the problems you are noticing. And going to a higher octane will fix the issue, as you discovered. Usually using a higher octane is just a waste of money, but in this case since it seems to have fixed your problem it is more than worth the extra $1.50/tank.
:)
 

·
Registered
Joined
·
901 Posts
How in the hell do you get 450 miles to the tank in a v6 mtx????


I avg 330-350 and just got 380 on a full round trip to ames IA

BTW...89 contains ethanol.... and ethanol = bad
 

·
Registered
Joined
·
701 Posts
Discussion Starter #5
:D
How in the hell do you get 450 miles to the tank in a v6 mtx????
I avg 330-350 and just got 380 on a full round trip to ames IA

BTW...89 contains ethanol.... and ethanol = bad
[/b]
1st off, in Wisconsin, ALL Gas has Ethanol :swearin: .

2nd. 80% HWY brother (75-85mph). The Auto Climate Control likes to run the A/C, I try to monitor that really well. I will upload my Trip of my next 3 tankfuls. I am also not racing around everywhere. I have moments of heavy throttle, but I don't run it that hard. Shift @ 3500RPM. Hell, I usually have 250 miles by the Half.
 

·
Registered
Joined
·
1,708 Posts
How in the hell do you get 450 miles to the tank in a v6 mtx????
I avg 330-350 and just got 380 on a full round trip to ames IA

BTW...89 contains ethanol.... and ethanol = bad
[/b]
I average 29.5 mpg highway in a V6 ATX. At that rate, I would get 413 miles using only 14 gallons. 450 for a full tank doesn't seem all that difficult to believe to me.
 

·
Registered
Joined
·
901 Posts
:D

1st off, in Wisconsin, ALL Gas has Ethanol :swearin: .

2nd. 80% HWY brother (75-85mph). The Auto Climate Control likes to run the A/C, I try to monitor that really well. I will upload my Trip of my next 3 tankfuls. I am also not racing around everywhere. I have moments of heavy throttle, but I don't run it that hard. Shift @ 3500RPM. Hell, I usually have 250 miles by the Half.
[/b]
My last trip this weekend was to Ames IA, 180ish miles one way, 75 mph the entire way and back, and wasn't heavy on the throttle at all either. Only avg'd 24 mpg.
 

·
Registered
Joined
·
1,769 Posts
I average 20 100% city with 87 ( no ethanol) and 16/17.. yes... it really blows with 89 with ethanlol so I have a hard time believing in the test but, as long as it fixed your problem, its all good.
 

·
Registered
Joined
·
1,479 Posts
dam something must be up with my car then i have a i4 atx and i only get 300 max per tank:(. I think i should have it checked
[/b]
Well, your not the only one, I have a 3.0 ATX 05 and w/ my MS CAI I get about 310 a tank....I have NO idea how you MTX guys are getting such a drastically amount more than us ATX guys....I knew I should of bought the MTX.
 

·
Registered
Joined
·
2,828 Posts
dam something must be up with my car then i have a i4 atx and i only get 300 max per tank:(. I think i should have it checked
[/b]
Since I cleaned my filter, I am at 278 with half a tank at the moment.
It got pretty dirty that last time though and my milage really reflected it.
 

·
Registered
Joined
·
701 Posts
Discussion Starter #13
I just topped off my tank last night... 257 Miles to 10.2 Gallons (gauge was at 1/2 tank). I was alittle harder on it this week than normal, especially after this weekends ZoomZoom Live :drive: :D

Those of you who doubt the validity of the test; What possibly do I have to gain or lose by telling you guys? I’m not recommending a product (other than octane) and I’m not selling one of those stupid gas mileage tools. Just sharing.

As far as driving habits go, I carpool so I keep my driving pretty calm during the week, while they are in the car.

My Morning commute is like this. 3 miles of city to the expressway, expressway for 27 miles, then 5 miles of city to work. So it’s about 70 miles a day.

My car has about 15K miles on it.
 

·
Registered
Joined
·
195 Posts
I went Cleveland to Indianapolis 2 weeks ago. 400 miles. Only took me 3/4 of a tank. On the way home, exact same route, only took 5/8 of a tank.
 

·
Registered
Joined
·
507 Posts
I get a pretty consistent 24-27mpg in 65-70% highway driving. I have the feeling that I could get deep into the upper 20's on a highway trip if I was more economy-conscious.

400 miles on a tank is not unusual for me, and that's with ethanol additives.
 

·
Registered
Joined
·
153 Posts
i'm pretty heavy footed and i only get about 300 miles to a tank using 87
i am going to try to switch back to 89 and see what i get.
 

·
Registered
Joined
·
680 Posts
2004 6s MTX.

I use Microsoft Excel to track my fuel mileage. Last summer, I ran 15 consecutive tanks of Shell V-Power to experiment with fuel mileage. The V-Power was consistently worse by about 2-3 mpg. However, my engine did run noticeably smoother across the board.

My car usually gets Shell 87, and I also use FP60. I can easily achieve over 29 mpg on the highway. After forcing an extra gallon into the tank, I've taken the car beyond 500 miles before the seeing the amber light. The most I've driven between fillups is 540 miles with over a gallon to spare.
 

·
Registered
Joined
·
51 Posts
Ive owned four Mazda 6 models now (over 80K miles collectively) and all three 6S models were MTX. All of them driven mostly highway and they all achieved 28+mpg at one time or another. IVe NEVER seen a tank dip below 23mpg overall. This is in WI and MN by the way.
 

·
Registered
Joined
·
1,906 Posts
Can we talk more about octane? He posted some interesting info about different octanes, like 89 being smoother and more responsive. Can anyone comment on this?

There are plenty of MPG threads already.
 
1 - 20 of 25 Posts
Top