I have an 06 AP2 with 62k. I was perusing the forums and noticed that some people get up 30mpgs on the highway I get closer to 22-26. With a few weekend road trips coming up I figured I could use the extra gas mileage if I could get it. Billman always say's to do a compression test before attempting to adjust the valves. I had some time after work and decided to do a compression test to see where I saw. I started with Cylinder #1 and got results of 195, 225, 240 - and was like WTF . This was a new gauge and the numbers seemed to be getting progressively higher so I chalked it up to the tester being new. I moved on to Cylinder #2 and figured I would come back to 1 last here are the results -

#2 - 240, 240, 240, 240
#3 - 240, 250, 260, 250
#4 - 255, 260, 255, 255
#1 - 240, 240, 240, 240

I was slightly concerned with #3 because of the 20 PSI swing but the compression is still really strong. So here are my questions -

Will the car benefit from a valve adjustment even though the number seem pretty strong?
Should I be worried about #3 because the numbers aren't super consistent?
Is there anything else I should consider when trying to improve gas mileage?

 

I can still get 31mpg highway after 181k miles, typically 29ish. Can't comment on the compression numbers, but tight valves can decrease mpg primarily at low engine speeds. It's a very simple task though and should take you less than an hour if you decide to embark. Many members have seen valves out of spec in as little at 25k so it may be beneficial regardless. You'll need a couple bent feeler gauges, torque wrench, hex wrench mainly.

 

Same, the last time I filled up I calculated 29 and then some MPG. I tried doing a valve adjustment twice and while the second time was much better, it's still not perfect so I want it done well. I have 117k on the odometer.

 

29 that is ridiculous. what do you guys get for city?

 

Did you actually notice an increase in gas mileage after you adjusted your valves?

 

I get about 21-23 in the city. I gotta drive it harder!

 

I never got 29. More like 26/27.

Yes, I would recommend a VA even at 30k.

 

I might just check them tonight and see how off they are.

 

Less lead foot.
All the other maintenace up to spec?
Tire pressure?
Keep the top up.

 

My tire pressure is good and all of the fluids are changed regularly. I put in a CAI and cleaned as much of the gunk in the intake manifold as i could with a rag. I don't know what else to do.

I will be taking a trip to VA this weekend. I will report the mileage if I make any adjustments to the valves before then.