Breaking-in a Volt properly may be difficult to do since the driver does not have direct control of the throttle.

To properly break-in any engine it should be:
1. warmed up first, gently
2. driven fairly aggressively with frequent stops for about 20 miles.
3. get an oil and filter change

Since most people are terrified of pegging a new engine to full rpm the owner's manual wont tell you this. The factory has already ran the engine (in a dyno) to full power for a couple of minutes, to verify that it works properly and to do a partial break in.

The bore of the engine is rough, it has been scratched in a crosshatch pattern when it was manufactured.. these scratches serve two functions, to quickly wear-in the piston rings so they seat fully against the bore and to retain a film of oil to lubricate said rings. The roughness at the edge of the scratches is what wears-in the rings in the first 20 miles it has been driven.. once that roughness quickly wears off then the seating-in process will slow down or completely stop.. your new engine will never perform right if the rings have not fully seated.. it will consume more oil and it wont develop as much power.. I know it seems contradictory but after those first 20 miles the ring wear stops almost completely. You need to drive it hard since the high combustion pressures force the rings to expand hard against the bore, also you need to slow down often so that high crankcase vacuum can suck metal particles and chips out from behind the rings and down into the oil.. and then you do an oil/filter change to get rid of those chips.

This is how I would break-in a Volt:

1. get on a lightly traveled hwy, drive the car normally until the battery is depleted, about 40-60 miles.
2. once the genset starts up, continue driving normally until it warms up.. perhaps 5 minutes?
3. Lower all windows, turn on your headlights to high beams, crank up the AC (or heater) to maximum, set the car in Mountain Mode and start driving fast.. up to 80mph is fine, drive like that for a couple of minutes and then slow down to 45 for a few seconds then crank it up again. Dont drive it at a constant speed.. hopefully the computer will rev the genset up and down and that is what we want..
4. change the oil and filter.

Perhaps GM will go the extra mile and run the engine at the factory a bit more than normal. Note that the engine must be loaded while doing this.. just reving it up while parked wont do anything to break it in.

Good post herm. It would be interesting to hear wot,s response. I am not sure if the oil filter and oil would be required so soon. (Using droid keyboard I have an. Excuse chrisc.:))

That's not how GM recommended breaking in the engine on my Enclave. From page 9-16 of the owner's manual (linked below)

http://www.buick.com/assets/en/pdf/owners/manuals/2010/Buick_Enclave_OM_2010.pdf

New Vehicle Break-In
Notice: The vehicle does not
need an elaborate break-in. But it
will perform better in the long run
if you follow these guidelines:

* If you have all-wheel drive,
keep your speed at 88 km/h
(55 mph) or less for the first
805 km (500 miles).

* Do not drive at any one
constant speed, fast or slow,
for the first 805 km
(500 miles). Do not make
full-throttle starts. Avoid
downshifting to brake or
slow the vehicle.

* Avoid making hard stops for
the first 322 km (200 miles) or
so. During this time the new
brake linings are not yet
broken in. Hard stops with
new linings can mean
premature wear and earlier
replacement. Follow this
breaking-in guideline every
time you get new brake
linings.

* Do not tow a trailer during
break-in. See Driving
Characteristics and Towing
Tips on page 9‑45 for the
trailer towing capabilities of
your vehicle and more
information.

Following break-in, engine speed
and load can be gradually
increased.

I still would recommend my way, but the thing about the brakes and towing is good advice.. of course the manufacture is not concerned about engine longevity way after the warranty is past.. and that is what my procedure is good for.

Perhaps GM will go the extra mile and run the engine at the factory a bit more than normal. Note that the engine must be loaded while doing this.. just reving it up while parked wont do anything to break it in.

Very interesting post herm. I do hope GM will take care of break-in, perhaps via 30 minutes on dyno or something, since we obviously don't have the ability to control the engine cycling. I'd be particularly interested in whether there will be a recommendation against long distance (CS mode) driving in the first XXX miles, because the very first thing I will do with mine is drive it 600 miles from dealer to home! I might spend a day in the Washington DC area first, just to do a little sightseeing (and possible car showoff) and to be near the dealer in case there are some Day 1 mortality events.


Good post herm. It would be interesting to hear wot,s response. I am not sure if the oil filter and oil would be required so soon. (Using droid keyboard I have an. Excuse chrisc.:))

Boy, I complain once about "its" vs "it's" and suddenly I'm the poster boy for spelling nazis? Typos I don't mind -- it's grammatical errors that put my brain into vapor lock. So, please, typo away :)

I also wanted to note that perhaps GM is taking extra steps to insure the engine bores are machined in a very uniform round shape.. thus reducing the need for break-in. Bolting the head on can deform the block, sometimes manufacturers apply stress to a block during bore machining, to make sure it ends up very round.

This bears watching and following up. I definitely remember the talk in owners' manuals about no agressive starts, but also not staying at any one speed. It seems that breaking in an engine has gotten much easier over the years. But for the Volt there surely must be some differences. And with the computer controls... well, who knows?

Great post/thread Herm.

I don't know if they still do this, but, the manufacturers used to put in special 'break-in' oil that shouldn't be changed the first day.

I do remember on a few of my new cars that they recommended not doing a sustained speed (high or low) for the first couple hundred miles. Varying the speed seems to be an important part of good break-in.

I also wouldn't recommend putting in synthetic oil until after the break-in period. Synthetic is so slippery that the engine parts won't seat together (such as rings against cylinder bore) properly.

For the 2011 Chevrolet Volt -
New Vehicle Break-In
Notice: The vehicle does not require a break-in period. Vehicle break-in is performed during manufacturing.


Hope this helps!
Angie - Chevrolet Volt Advisor
socialmedia@gm.com

Great post/thread Herm.

I also wouldn't recommend putting in synthetic oil until after the break-in period. Synthetic is so slippery that the engine parts won't seat together (such as rings against cylinder bore) properly.

The engine will come with DEXOS1 in it, which is a synthetic blend.

Many new cars today come from the factory with synthetic oil and have change intervals of 10k to 15k miles including the first change. Today's engines are much diff from the old Chevy v8s from years ago that needed a different break in. Change intervals should be decided by the weather conditions you drive in and if the engine always warms up thoroughly each time you use it. In any case today's engines don't need the 3k changes unless the time interval is to long with very low mileage. Synthetic doesn't break down but it still gets dirty.

You may be right, and it probably couldn't hurt, but most manufacturers did away with this kind of break-in procedure many years ago. Cars used to come shipped with "break-in oil" for this very purpose. But still, it's not a bad idea.


Breaking-in a Volt properly may be difficult to do since the driver does not have direct control of the throttle.

To properly break-in any engine it should be:
1. warmed up first, gently
2. driven fairly aggressively with frequent stops for about 20 miles.
3. get an oil and filter change

Since most people are terrified of pegging a new engine to full rpm the owner's manual wont tell you this. The factory has already ran the engine (in a dyno) to full power for a couple of minutes, to verify that it works properly and to do a partial break in.

The bore of the engine is rough, it has been scratched in a crosshatch pattern when it was manufactured.. these scratches serve two functions, to quickly wear-in the piston rings so they seat fully against the bore and to retain a film of oil to lubricate said rings. The roughness at the edge of the scratches is what wears-in the rings in the first 20 miles it has been driven.. once that roughness quickly wears off then the seating-in process will slow down or completely stop.. your new engine will never perform right if the rings have not fully seated.. it will consume more oil and it wont develop as much power.. I know it seems contradictory but after those first 20 miles the ring wear stops almost completely. You need to drive it hard since the high combustion pressures force the rings to expand hard against the bore, also you need to slow down often so that high crankcase vacuum can suck metal particles and chips out from behind the rings and down into the oil.. and then you do an oil/filter change to get rid of those chips.

This is how I would break-in a Volt:

1. get on a lightly traveled hwy, drive the car normally until the battery is depleted, about 40-60 miles.
2. once the genset starts up, continue driving normally until it warms up.. perhaps 5 minutes?
3. Lower all windows, turn on your headlights to high beams, crank up the AC (or heater) to maximum, set the car in Mountain Mode and start driving fast.. up to 80mph is fine, drive like that for a couple of minutes and then slow down to 45 for a few seconds then crank it up again. Dont drive it at a constant speed.. hopefully the computer will rev the genset up and down and that is what we want..
4. change the oil and filter.

Perhaps GM will go the extra mile and run the engine at the factory a bit more than normal. Note that the engine must be loaded while doing this.. just reving it up while parked wont do anything to break it in.

Angie's response seems to clear it up... No break in needed. Thanks Angie!