Lousy mileage after oil change please help
09-30-2016, 01:11 PM
#1
Lousy mileage after oil change please help
So I've had my Vette for about five months now. When I got it I was getting between 22-24 mpg everywhere I went. Sometimes higher. I got the oil changed a couple months ago after I put about 4k on it and it went down to 16.5 and no matter how I drove on the highway or around town it stuck between 16.4 and 16.5...
So today I took it and got the oil changed again after another 3k plus got k&n airfilters for both sides and jesus christ I'm getting less mpg at 15.8. I took it out and drove it about 50 to 60 miles just to see if it needed to balance itself but never got over 15.8.
The oil change was $70 because I had to have someone do it then another $100 for both air filters. What the heck is going on with this thing!!! I put the M1 synthetic like it calls for in it and the filters are the best you can buy. I don't drive it with a lead foot...seriously this is making me sick.
So today I took it and got the oil changed again after another 3k plus got k&n airfilters for both sides and jesus christ I'm getting less mpg at 15.8. I took it out and drove it about 50 to 60 miles just to see if it needed to balance itself but never got over 15.8.
The oil change was $70 because I had to have someone do it then another $100 for both air filters. What the heck is going on with this thing!!! I put the M1 synthetic like it calls for in it and the filters are the best you can buy. I don't drive it with a lead foot...seriously this is making me sick.
09-30-2016, 01:19 PM
#2
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Both side of what?
Are you checking instant fuel economy??? Average fuel economy???
Have you reset you average fuel economy?
Perhaps when the oil life is reset it wipes out the miles in the average fuel economy memory bank.
Hit reset, take a drive, and check it again.
Are you checking instant fuel economy??? Average fuel economy???
Have you reset you average fuel economy?
Perhaps when the oil life is reset it wipes out the miles in the average fuel economy memory bank.
Hit reset, take a drive, and check it again.
09-30-2016, 01:19 PM
#3
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So I've had my Vette for about five months now. When I got it I was getting between 22-24 mpg everywhere I went.
I got the oil changed a couple months ago after I put about 4k on it and it went down to 16.5
So today I took it and got the oil changed again after another 3k plus got k&n airfilters for both sides and jesus christ I'm getting less mpg at 15.8
______________________________
In all reality, there is absolutely nothing in an engine oil / oil filter change that can lower your gas mileage ... nothing at all.
You have something else going on here.
09-30-2016, 01:32 PM
#4
C6 has two air filters on each side of the instake. I put new ones in both sides.
I've reset the gauge and that's the first thing I do after I get an oil change just to be sure I'm going off the new oil. That's average fuel economy too.
I figure it's something else besides the oil and air filters, but it's just weird to have a decrease exactly when I change out those two items...
I've reset the gauge and that's the first thing I do after I get an oil change just to be sure I'm going off the new oil. That's average fuel economy too.
I figure it's something else besides the oil and air filters, but it's just weird to have a decrease exactly when I change out those two items...
09-30-2016, 01:37 PM
#5
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C6 has two air filters on each side of the instake. I put new ones in both sides.
I've reset the gauge and that's the first thing I do after I get an oil change just to be sure I'm going off the new oil. That's average fuel economy too.
I figure it's something else besides the oil and air filters, but it's just weird to have a decrease exactly when I change out those two items...
I've reset the gauge and that's the first thing I do after I get an oil change just to be sure I'm going off the new oil. That's average fuel economy too.
I figure it's something else besides the oil and air filters, but it's just weird to have a decrease exactly when I change out those two items...
09-30-2016, 01:38 PM
#6
You must have an aftermarket air intake set up as the stock filter is a one piece element. Check your mileage by the only reliable way...fill it up...drive....fill it up again....note mileage and divide by the gallons taken on the second fill up.
09-30-2016, 01:40 PM
#7
I did. I reset both for sure. Oil life is 100% mpg 15.8 steady after 60 mile drive. The sensors not off because I can see the fuel gauge dropping pretty fast compared to when I first got it. Could it be dirty injectors or something like that?
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09-30-2016, 01:45 PM
#10
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And the only [accurate] way to check your gas mileage is to:
1. Fill the tank completely
2. Record the total miles on the car at this point
3. Drive until the tank is close to being empty
4. Fill with gas again and see how many gallons it took (to the 10th of a gallon) to get it full again
5. Notice your total miles on the car at this time of re-filling
6. Subtract your total miles on the car now by the miles that were previously on the car before
7. Divide these miles by the total gallons of gas (to the 10th of a gallon) you needed to put in the tank to refill it.
> > This is the ONLY accurate way to check your miles per gallon
1. Fill the tank completely
2. Record the total miles on the car at this point
3. Drive until the tank is close to being empty
4. Fill with gas again and see how many gallons it took (to the 10th of a gallon) to get it full again
5. Notice your total miles on the car at this time of re-filling
6. Subtract your total miles on the car now by the miles that were previously on the car before
7. Divide these miles by the total gallons of gas (to the 10th of a gallon) you needed to put in the tank to refill it.
> > This is the ONLY accurate way to check your miles per gallon
09-30-2016, 01:50 PM
#12
I drive till it's at an 8th almost everytime before filling it again to halfway. So I need to completely fill it up I guess. I'm getting ready for a 1k trip next week so I'll see what happens then, but jesus I bet I'm gunna spend between 3-4 hundred in gas with 15.8 mpg.
Last edited by Lobzpooatu; 09-30-2016 at 01:50 PM.
09-30-2016, 01:52 PM
#14
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To accurately check your gas mileage ... You need to do it just like I wrote above
Any other way is just a "swag" !
Any other way is just a "swag" !
09-30-2016, 01:55 PM
#16
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Again, check your mileage the way I told you.
Enjoy your trip
09-30-2016, 02:00 PM
#18
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I guess we need to ask what year/model/mileage/trans, etc...
09-30-2016, 02:08 PM
#19
Le Mans Master
Road trip on the freeway gets me almost 30 mpg. Mountain roads are at well under 20 mpg.
I have the same dual air filters on my 2007. Bought them for $12 each and installed them in two minutes. No tools required. Just do it your self next time.
I have the same dual air filters on my 2007. Bought them for $12 each and installed them in two minutes. No tools required. Just do it your self next time.