"I think we have not peaked as a team performance-wise," said Earnhardt, who also won the season-opening Daytona 500. "We have a lot of passion and emotion, considering this is Steve's last year."
Steve Letarte, Earnhardt's crew chief, will become a racing analyst for NBC Sports, which takes over NASCAR coverage next year.
Recalling the day in Homestead, Fla., last November after the season finale when Letarte told him he was moving on, Earnhardt said: "He said, 'I've got to tell you what I'm doing.' I broke down. It was the hardest thing to have to hear, but I thought, 'We've got 1 year together, so let's have some fun.'
"I'm real happy for him to be able to do this thing. Racing is an important part of our lives, but it's not the most important thing. He's going to be financially set, he's going to be able to spend a ton of time with his kids, play as much golf as he wants. He's getting a steal, compared to what he's doing right now."
Replying to a question about detractors who still insist Earnhardt is overrated despite 21 Cup series wins, he laughed and said, "I don't worry about that as much anymore. I'm turning 40 this year, and the overrated talk is way behind me."
Letarte, from Portland, Maine, is only 35. He is in his fourth year as Earnhardt's crew chief. Previously, he was Jeff Gordon's crew chief, earning consecutive Chase berths from 2006-10. Letarte could easily continue as a high-level crew chief for 10 or more years, but wants more time with his family.
"You guys [media] only see the great stuff, a win at Daytona and a win here," he said. "But Saturday of Kansas [May 9], my little girl had her first Communion and I was in Kansas. When moments like that happen, it reaffirms why I made my decision.
"I love my job. I love the people I work with, but I chose 9 to 10 years ago to have a family. They have to come first."
It's unlikely Rick Hendrick can take a chance on a crew chief with no Cup series experience to succeed Letarte, but he also must find someone who gets along with Earnhardt.
With two wins already this year, Earnhardt thinks his No. 88 Chevrolet team will be a serious threat in the Chase.
"It makes it fun, because you can just go to the racetrack and just race and not worry about points," he said of his current standing. "It's a lot less stress, and I think that could be a good thing going into the Chase. That's got to be a positive for our composure and psyche going into the Chase."
Earnhardt is a two-time winner at Michigan, site of Sunday's race. His victory at Michigan 2 years ago ended a 143-race winless slump. In last June's race at the track, he led the second-most laps (34) until an engine blew.
Another pioneer gone
NASCAR lost another of its longtime admired figures. W.C. "Junie" Donlavey, a car owner from 1949 through 2005, died Monday night at age 90.
As a team owner, Donlavey only won one race, with Jody Ridley at Dover International Speedway in 1981. But the Virginia native helped develop many drivers in his No. 90 Ford, including Buck and Buddy Baker, Benny Parsons, Cale Yarborough, Joe Weatherly, Ricky Rudd, Ken Schrader, Ernie Irvan, Bobby Isaac and Rick Mast.
Donlavey has been described as "probably the most well-liked person ever in NASCAR."
"He was always a joy to have around the track, and our thoughts and prayers are with his family," said Denis McGlyn, president and CEO of Dover Motorsports.
In 2002, the Eastern Motorsports Press Association established the Junie Donlavey Spirit Award, which is presented each year to individuals who best represent independent spirit of the sport and perform tasks behind the scenes to improve the sport. Donlavey was the first recipient.
Donlavey added "International Motorsports Hall of Fame Member" to his accomplishments when he was inducted in 2007.
This week's race
Quicken Loans 400
Michigan International Speedway, Brooklyn, Mich.
When: Sunday, 1 p.m.
TV/Radio: TNT/WNPV (1440-AM)
Course: 2-mile oval
Distance: 200 laps/400 miles
Forecast: Mostly sunny, low 80s
Last year’s winner: Greg Biffle
Last year’s pole: Carl Edwards, 202.452 mph
Track qualifying record: Joey Logano, 203.949 mph (August 2013)
Track facts: Greg Biffle gained his fourth Michigan win, most among active full-time drivers, last year by leading 48 laps, including the last 32. Kevin Harvick was runner-up; Martin Truex Jr. was third. Polesitter Carl Edwards led 16 laps and finished eighth. Joey Logano won the August race at Michigan ... Greg Erwin, from Hatboro, is Juan Pablo Montoya’s crew chief this weekend and also at the Brickyard 400 at Indianapolis July 27. Montoya is driving the No. 12 team Penske Ford for the two races. He is seventh in IndyCar series points ... Rookie Kyle Larson’s three top-five finishes this year equal the number veterans Kyle Busch, Kurt Busch and Carl Edwards each have.
Wins: Kevin Harvick, Joey Logano, Jimmie Johnson, Dale Earnhardt Jr., 2 each; Brad Keselowski, Carl Edwards, Kyle Busch, Kurt Busch, Denny Hamlin, Jeff Gordon, 1 each.
1. Jeff Gordon 498
2. Matt Kenseth 482
3. Dale Earnhardt Jr. 476
4. Jimmie Johnson 475
5. Brad Keselowski 448
6. Kyle Busch 443
7. Carl Edwards 441
8. Denny Hamlin 420
9. Joey Logano 418
10. Kyle Larson 417
11. Ryan Newman 411
12. Kevin Harvick 403
13. Brian Vickers 392
14. Greg Biffle 385
15. Austin Dillon 385
16. Clint Bowyer 383
Up next: Toyota/Save Mart 350, June 22, Sonoma Raceway, Sonoma, Calif., 3 p.m.; TV: TNT; last year’s winner: Martin Truex Jr.