ZL1 to M5
 

Buddy of mine is looking at both, but strongly favors M5 (as of now) - more room of course, but also more refined/smoother, and AWD makes it a rocket off the line. Amazing a turbo 4.4 with more weight can beat a ZL1 0-60, and reportedly the car makes a true 600+ rwhp bone stock (underrated by BMW) - a testament to turbo power vs parasitic sc losses.

Too bad there isn't a 3000 lb car out there bred for the track with this same engine, it would sell like crazy.

Any horror stories with M5 (current generation) reliability?

No trouble as I know.. except from the battery as our zl1..

Very different cars. M5 actually has a back seat and runs 10's.

BMWs are great cars while under warranty. After warranty it can get really expensive.

Sadly, that's not really a good reputation to have. I've heard countless stories of BMW's requiring constant trips to the dealer for repair. Its great that its covered under warranty but who wants to take their car in all the time? I modified my ole' American Dodge Hellcat to 1000hp and drove it 3 1/2 years, never needed the warranty once.

That’s why I’m here today. Traded in my pristine v10 M5 for my 1LE.

All I had was exhaust intake and it was lowered. I loved that car and kept it immaculate.

But regular maintenance was expensive. $550 for an oil change at the dealership. Any additional repairs you needed a second mortgage.

I decided to go back to my roots and went back to Chevy.

You're right that BMWs (and Porsches) are underrated at the crank. But the difference isn't parasitic losses due to the s/c on the ZL1: The ZL1 is rated at 650 crank hp after accounting for the power it takes to drive the supercharger. It's just that BMWs are underrated. Car and Driver dyno'd an M5 Comp and it made 617 whp. Granted, the M5 Comp is a little more powerful than the regular M5 but the M5 probably isn't that far behind.

Being underrated helps explain why the M5, a 4-door sedan that weighs 4,288 lbs can do 60-130 mph in 8.3 seconds (per C&D) and trap 129 mph in the 1/4 mile while the A10 ZL1 does 60-130 mph in 8.9-9.0 seconds and traps 125-127 mph in the 1/4 mile, despite weighing 365 lbs less, and "supposedly" making 50 more hp.

The M5 is has a lower drag coef. than the ZL1, which may explain why the 60-100 mph times are closer between the two cars, percentage-wise (3.8 sec for M5 vs. 4.0 sec for the A10 ZL1; about 5% difference) compared to the gap widening as speed grows: 100-130 times for the M5 and ZL1 are 4.5 sec and 5.0 sec, respectively (an 11% difference).

That said, have your friend watch the Throttle House M5 Competition video review on YouTube - they do a full review and they said it is numb to drive. It's very fast, but numb.

Don't own one out of warranty.

I didn't own an M car but my 2012 135i only ever went in for regular maintenance (wasn't babied) and it came with a 5 year maintenance plan (yes, no extra change unlike now where they charge you X amount for Y year maintenance). So free oil changes, trans fluid changes, yearly wiper blade changes, etc. Then after the warranty was over, it still never gave me issues.

I never had issues except minor annoyances like the rain sensitive wipers and navigation that gave you wrong directions.

Though I was caught off guard about the battery replacement costing over $300. $150 for the battery (because you HAVE to get the exact same battery) and then another $150 to "pair" the battery to the car.

The V10 M5 is one of those cars that gives BMWs a bad name. You can search the internet and read on why it's not a great car to own..... unless you never drive it.

Great sounding car but one that people should avoid. Unlike the newer M5's. Nothing bad on them from what I've read and heard.

after that AWD starting line advantage, our cars pull on the new M5. It isn't much but from 50-150 my previous 2017 ZL1 was a bit faster than an M5 at VIR on the straight. They guy is a friend of mine and he gives me NO slack.

It might be good, definitely is, but it's still only an insanely expensive BMW in the sea of near identical, sterile, German engineered BMWs.

Like in Clint's movie, the Good the Bad and The Ugly
The Good, Safety. BMW's are awesome, if he has a family and they're going to ride in the car, I'd go this way. My personal experience....
Owned a 2001 325i. I totally credit it with saving my life or at the very least my legs in a major accident where the car rode so nice and I was so sleep deprived from working, I fell asleep in rainy weather at 40MPH and spinning hit a tree broadside right where my legs were. The passenger compartment had minimal distortion. If the side and front airbags had not been disabled by me, I probably would have walked away without a scratch (Japanese wife liked baby in the front seat... what to do, I like pvssycat...). However, I lost my shoulder connective tissue trying to brace myself for impact as I woke up just before the tree. Since I was an intraining powerlifter at that time, I had some serious pressure on the wheel as I eggshaped the steering wheel on a side impact and bent the seat substantially (I don't remember, but I must have been really pressing hard cause I only weigh 160lbs). Nevertheless, I walked away.... (with a very sore surgery needing shoulder). And that surely would have never happened in my Aluminum alloy with no real frame RX-7.

The Bad.... You can't work on these unless you have BMW style Tools, or at least you couldn't then. Anything you want do to the car, you got to go to BMW. And to me, a guy that likes to change the brakes myself, I hated this.

The Ugly.... When you do go into BMW to get what ever you want done, do not go in with less than $500 in your pocket to lube your anus for the simple things, more complicated add an extra grand. And simple stuff would break, the window cable $400, wanted to upgrade my girl's BMW stereo, $800. It's freak'in ridiculous. And that was just the beginning, it got worse.

So to sum up my post, if he has and cares about the security of his family, the BMW is awfully nice, it surely saved my butt, they had to have a super forklift to clear my strewn car off the highway, but the passenger compartment safety is unmatched. If he cares about money and ease to mod the car and (to me) looks of the car, go ZL-1.

Sure I recognized that - they're separate points but both are true, the main point is turbo power potential is greater, plus reduced weight in general, that 4.4L is impressive

Right - and the ZLE is even worse

Yep - similar comments on the detailed savagegeese review and others, but the M5 is more of a performance/luxury sedan

Good points, thanks - and I'm a Clint Eastwood fan