Towing our Chevy (Corvette) with a Chevy (Suburban) | Project C5 Corvette Z06

Update by J.G. Pasterjak to the Chevrolet Corvette Z06 project car
Jun 9, 2021

We’re loaded and ready to roll to Bowling Green, Kentucky, with our Project Ultimate Corvette for the Tire Rack SCCA Time Trials Nationals Powered by Hagerty.

But we've got a surprise hauling the C5.

Usually, we load it up behind our 2010 Toyota Tundra, but a recent conversation with Chevrolet went like this:

"Have any needs to test tow-capable trucks in actual towing situations?"

"Well, yes, we do."

So when TTN rolled around, we borrowed a 2021 Suburban equipped with the 3.0-liter Duramax turbo diesel inline-six that cranks out a whopping 460 lb.-ft. of torque. The Suburban also features several trailer-friendly options, like auto-leveling and a built-in trailer management app.

So far, we’re impressed. We did 60 miles of errand running around town yesterday—all city driving—and the Suburban averaged 26.2 mpg. That’s just nuts. We’re excited to measure the truck’s performance and efficiency once towing the Corvette.

Speaking of Corvettes and efficiency, we’ll be running Sunoco E85 at TTN. Last week, we visited Redline Tuning Services, our local LS tuning guru in Daytona Beach, and the folks there put together an E85 tune that made horsepower and shed heat.

[How to make more power with E85.]

The only downside to running E85 is that you run a lot of it, so efficiency is reduced. Luckily, it’s less expensive than regular gas: Local E85 prices are $2.29 per gallon, and it tests right at 85% ethanol.

Our drum of Sunoco E85-R will meet us at the event, so we’ll have reliable, cool and consistent power on tap all week.

[What's the difference between race fuel and street fuel?]

TTN will also mark our first event on the new Goodyear Eagle RS R-compound tires. These tires recently scored GT2 class wins at an SCCA Majors event. We’ll find out more after our first sessions at NCM Motorsports Park.

Look for us on the road late Tuesday and all day Wednesday. If you see us, wave.

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View comments on the GRM forums
yupididit GRM+ Memberand PowerDork
6/8/21 6:35 p.m.

26mpg is crazy. Impressive!

Toyman01 + Sized and
Toyman01 + Sized and MegaDork
6/8/21 7:46 p.m.

3.0 inline 6 diesel? Thats intriguing. I wonder it it would fit in my XJ. 

JG Pasterjak
JG Pasterjak Production/Art Director
6/8/21 8:55 p.m.

Day 1 update. 360-ish miles, 18mpg towing the Corvette. I'm impressed.

Tom Suddard
Tom Suddard GRM+ Memberand Director of Marketing & Digital Assets
6/8/21 9:05 p.m.

Wow. That's seriously impressive; I figured you'd be down in the mid-teens.

So are you buying one? Because the last tow vehicle you borrowed and enjoyed was that Tundra....

Sonic UltraDork
6/8/21 9:24 p.m.

That mileage is very compelling.


This weekend I also towed my new-to-me Corvette with my Suburban, but your are both much nicer and get 2x the towing mileage.  

dxman92 Dork
6/8/21 10:07 p.m.

Impressive mileage to say the least!

thashane GRM+ Memberand New Reader
6/8/21 10:27 p.m.

I like inline 6's. I like diesels. You can tell Chevy I had no idea they made a babymax. I rented a Tahoe last year, and it was really nice, and scooted for its weight. 

engiekev HalfDork
6/9/21 7:17 a.m.

That 3.0 LM2 is a fantastic engine! The driveability, response, and fuel economy blow away even recent diesels. I've driven a few, and now the 3.0 diesel in our cayenne feels downright slow and laggy in comparison! It really is that much of an improvement.  Perfect engine for highway cruising, not as great for solely city driving since you won't be getting any regens.

It's also a great fit for the trucks. Unfortunately it's not available in the at4 or z71 packages on the SUVs, that would be a fantastic package!

Powar GRM+ Memberand UltraDork
6/9/21 9:06 a.m.

I reaaalllllly would like to trade in our 6.2 Escalade ESV on a new one with the Duramax 6 in it, but I'll have to settle for someone's old and busted one in a few years.


Our old diesel Suburbans fit our needs perfectly. I'm really glad GM is doing it again.

Toyman01 + Sized and
Toyman01 + Sized and MegaDork
6/9/21 9:47 a.m.

So what are our thoughts on the wet belt-driven oil pump? They have a 150k inspection interval, and you have to pull the transmission to do that. 

engiekev HalfDork
6/9/21 9:59 a.m.
Toyman01 + Sized and said:

So what are our thoughts on the wet belt-driven oil pump? They have a 150k inspection interval, and you have to pull the transmission to do that. 

It is not easy to access, same procedure needed for the timing chain drive.  If chain stretch or tensioner wear becomes a concern, hopefully that occurs while still under warranty!  You can see both the timing drive and oil pump drive here:

Duramax 3.0 LM2 Crate Engine | DMAX Store

Is the 3.0L Duramax Living Up To the Hype? | DrivingLine

However, even it if was on the front of the engine, it still wouldn't be an easy job.  That is the drawback of inline 6s, even in the massive trucks packaging is an issue:

3.0L LM2 Duramax Specs, Fuel Economy, and Towing Capacity

mdshaw GRM+ Memberand Reader
6/9/21 10:01 a.m.

The timing chain locations are unfortunate. Too bad they aren't gear driven. How is the exhaust fluid usage?

Toyman01 + Sized and
Toyman01 + Sized and MegaDork
6/9/21 10:07 a.m.

In reply to engiekev :

If it was a chain I wouldn't worry about it. I'm reading that it's a rubber belt and a rubber belt running in oil is a bit more concerning. 


engiekev HalfDork
6/9/21 10:35 a.m.
Toyman01 + Sized and said:

In reply to engiekev :

If it was a chain I wouldn't worry about it. I'm reading that it's a rubber belt and a rubber belt running in oil is a bit more concerning. 


Yes, see the pics, it is a oil bath driven belt.  Many manufacturers have gone this way, but I'm not sure on the reliability front.  Chains aren't perfect either, they stretch and wear, but its curious why they didn't use a gear driven oil pump, likely for NVH.

Toyman01 + Sized and
Toyman01 + Sized and MegaDork
6/9/21 11:31 a.m.

Since I'm the guy that buys these things at 150k+, reliability will be worth keeping an eye on. 


yupididit GRM+ Memberand PowerDork
6/9/21 2:14 p.m.

I had planned on driving my 2015 Expedition for about 10 years then get a used diesel Escalade. 

But, if Ford makes an EV version of the Expedition, then I might go that way. 

Too many awesome options. Gotta find a diesel Burb to test drive now. 

Paul_VR6 (Forum Supporter)
Paul_VR6 (Forum Supporter) SuperDork
6/9/21 2:21 p.m.

VR6 guy here checking in to chuckle about future timing chain service GOOD LUCK!! cool

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