1998 Bonneville. What rpm should I see on the tach at 70mph while cruising on the highway? No check engine light, all stock, 105,000 miles clean fluid runs great but mileage seems down. It runs about 2200 or 2300 rpm at 70mph. Seems like maybe the lock up isn't working? Comments. I did search forum and read some of the overdrive threads.
JP

That'* what mine runs at. Sometimes, if I'm keeping a steady speed, it'll shift up. Then, it goes down to 1500 RPM, and I give it gas to get it to downshift again, because 1500 seems WAY too low to be going 70. But sometimes when mine'* cold and I run it that fast it can go up closer to 2500, but I'd say anywhere around 2000 is the normal range for a 3800 Series II

I forgot to add that I never drive in overdrive, I keep it in the standard one for "better performance," but I've never noticed much of a difference. Maybe it'* just me.

You should have about 2000 to 2100 in OD.

Thanks guys. Just bought a 2002 Bonneville and it shows roughly 1600 rpm at 70mph. Our 4th Bonneville. Hey Dan nice pics on your web site. I see you have wealth of information these cars. I hoped you would have a reply for this question being in Wis.
JP

Where about in WI are you. I'm a hour north of Milwaukee right between Milwaukee and Green bay. Any other questions, just ask and I'll be happy to answer best I can.

Dan,
8 miles east of Rhinelander. I have few more questions most likely this week. Just bought a 02 Bonne for the wife. You help / experience is greatly appreciated. I try to search forum before posting any questions.
Thanks,
JP

I've been up that way. Got family around Marshfield. If you can't find what you need, just ask and I'll do what ever I can.

Hi, the rpm by 135mph is 3500 by my 92 SSEi